JPH10147133A - Communication error determining device for vehicle air-conditioning system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication error determining device which can reduce a vehicle air-conditioning system for driving under control a plurality of door actuators and the system cost, and which can determine a communication error when a communication line is short-circuited, by introducing a LAN system between amplifiers and the door actuators. SOLUTION: An air-conditioning amplifier unit (g) is connected to a plurality of door actuators (d, e, f) through a single communication wire (h). Response signals having a high level which indicates the operation of the door actuators (d, e, f) or a low level which indicates stopping of the door actuators are added to communication data. The amplifier unit (g) is provided therein with a self- diagnosing means (j) for determining a normal if the response signal which is checked with a time lag from the time when an instruction value is changed is low, but for determining an abnormal if the response signal is high, and a first communication error determining means (k) for comparing transmitted data with received data so as to determine a communication error caused by a short-circuit to be ground if a signal in the received data corresponding to a signal having a high level in the transmitted data has a low level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a LAN for connecting an air conditioner amplifier unit (master station) and one or more door actuators (slave stations) via one communication line and one power line. (Local area network
network) and belongs to the technical field of a communication error determination device for a vehicle air conditioner system that controls the opening of a plurality of doors.

[0002]

2. Description of the Related Art Conventionally, as an air conditioner system for a vehicle, for example, as described in Japanese Patent Application Laid-Open No. 6-8746, an air conditioner amplifier unit is provided with an actuator drive circuit for driving each door actuator, and an air mix door is provided. There is a known type in which actuators for a vehicle, a mode door, and an intake door are connected to a drive circuit by a harness.

[0003]

However, in the conventional vehicle air conditioner system, the drive circuit and each door actuator are connected by five to nine harnesses, respectively. In addition, each door actuator is of a different type, such as a potentiometer type or an encoder type, so that mass production effects cannot be expected.Furthermore, the size of the amplifier is increased by incorporating an actuator drive circuit into the air conditioner amplifier unit. Then, the microcomputer load also increases.

Therefore, a solution to these problems is to use a LAN in which the air conditioner amplifier unit and a plurality of door actuators are connected by a single communication line.

That is, by adopting the LAN, the number of harnesses can be reduced, the actuators can be integrated, and the size of the amplifier can be reduced. As a result, excellent advantages such as reduced system weight and reduced system cost can be obtained. Can be.

However, instead of the current system, LA
Even if an attempt is made to adopt an N-type system, the following problems must be solved.

In the current system, each door actuator is driven by a drive command signal from an actuator drive circuit of the air conditioner amplifier unit, and a feedback signal of the operating position is returned from the door actuator to the air conditioner amplifier unit in real time. By checking the feedback signal corresponding to the command signal, it can be determined in real time whether the door is normally opening and closing.

[0008] However, when the LAN is adopted, when the door target stop position data of each door is unilaterally transmitted to the door actuator in accordance with a predetermined rotation, whether it is normal or abnormal is determined. Check cannot be performed.

Therefore, a reply signal that is fed back from the door actuator to the air conditioner amplifier unit is added to the communication data. This reply signal is used to stop the operation and stop of the door actuator from the viewpoint of not prolonging the communication time. The signal is transmitted by the difference between the high and low signal levels.

In this case, the self-diagnosis of whether the system is normal or abnormal is performed by changing the indicated value from the air conditioner amplifier unit to the door actuator, checking the return signal after waiting for a delay in door operation and communication. When the return signal changes from high to low during the waiting time, and when the check timing is low indicating stop, it is determined to be normal, and when it is high indicating operation, it is determined to be abnormal. It is.

However, according to this self-diagnosis method, when the communication line is short-circuited to the ground, the return signal remains low, so that it is determined to be normal.

An object of the present invention is to provide a vehicle air conditioner system for driving and controlling a plurality of door actuators, in which a communication line is used while reducing the system weight and system cost by using a LAN between an amplifier and an actuator. An object of the present invention is to provide a communication error determination device capable of determining a communication error when a ground short circuit occurs.

[0013]

[Means for Solving the Problems]

(Solution 1) Solution 1 of the above problem (Claim 1)
As shown in the claim correspondence diagram of FIG. 1 (a), a controller b having an operation section a provided with switches such as a mode switch and a temperature adjustment dial, and a switch and sensors by a built-in microcomputer. The air conditioning system for a vehicle including an air conditioner amplifier unit g that drives and controls a fan motor c and a plurality of door actuators d, e, and f provided in the air conditioning system. The air conditioner amplifier unit g and the plurality of door actuators d, e, f are connected via one communication line h and one power line i, and from the air conditioner amplifier unit g to each door actuator d, e, f. Sequentially transmits instruction values, such as door target stop position data, via one communication line h. Yueta d, e, and communication format adding the reply signal of low indicating a high or stop showing the operation of f, the air conditioning amplifier unit g, door actuator d from the air conditioning amplifier unit g, e,
f, the return signal is checked after waiting for the delay time, and if the return signal is low, it is determined that the signal is normal, and if it is high, the self-diagnosis means j and the air conditioner amplifier unit g are determined to be abnormal. The first communication which compares transmission data to be output with reception data received by the air conditioner amplifier unit g and determines that a communication error due to ground short-circuit occurs if the reception data corresponding to a high signal level in the transmission data is a low signal level. It is characterized in that error determining means k is provided.

(Solution 2) The solution 2 of the above problem (claim 2) is, as shown in the claim correspondence diagram of FIG.
2. The communication error judging device for a vehicle air conditioner system according to claim 1, wherein said air conditioner amplifier unit g is instructed from said air conditioner amplifier unit g to said door actuators d, e, f instead of said first communication error judging means k. Checking of the return signal is started from the point of time when the value is changed, and the second communication error determination means m is provided for determining that a communication error has occurred due to a ground short if the return signal does not become high even after the set time has elapsed and remains low. It is characterized by having.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) Embodiment 1 is a communication error determination device for a vehicle air conditioner system corresponding to Solution 1.

First, the configuration will be described.

FIG. 2 is a diagram of a vehicle air conditioner system to which the communication error determination device according to the first embodiment is applied.

As shown in the upper part of FIG. 2, as the mechanical system of the air conditioner system, an intake unit case 1, an outside air intake port 2, an indoor intake port 3, a blower fan 4, a blower fan motor 5, an intake door 6, a cooling door A unit case 7, an evaporator 8, a heater unit case 9, a vent outlet 10, a differential outlet 11, a foot outlet 12, a heater core 13, a bilevel door 14, a mix door 15, a vent door 16, a differential door 17, and a foot door 18 are provided. I have.

The bilevel door 14 bypasses the air passage 19a provided with the heater core 13 disposed from the evaporator 7 via the mix door 15, and guides the cool air from the evaporator 7 to the vent outlet 10. It is provided in.

As shown in the middle to lower parts of FIG. 2, a fan control circuit 2
0, intake door actuator 21, bilevel door actuator 22, air mix door actuator 23, mode door actuator 24, air conditioner amplifier unit 25, water temperature sensor 26, refrigerant temperature sensor 2
7, inside air sensor 28, outside air sensor 29, solar radiation sensor 3
0, a suction temperature sensor 31, and a controller 32.

The fan control circuit 20 continuously controls the voltage applied to the blower fan motor 5 in accordance with a command from the air conditioner amplifier unit 25.

The above-mentioned intake door actuator 21
Is the intake door 6 in the air conditioner amplifier unit 25.
Is determined (inside air, semi-outside air, outside air), the intake door 6 is moved to the determined door opening.

The bi-level door actuator 22
In the vent mode, when the opening of the mix door 15 is full cold, or in the bi-level mode in which the temperature control is performed with cold head heat, the bi-level door 14 is fully opened, and in other cases, the bi-level door 14 is closed.

The air mix door actuator 23
When the virtual door opening XPBR is determined by the motor air conditioner amplifier unit 25, the mixed door 15 receives data of the virtual door opening XPBR and obtains a door opening that matches the virtual door opening XPBR. To work.

When the target mode door position is determined by the air conditioner amplifier unit 25, the mode door actuator 24 operates the mode door (vent door 16, differential door 1).
7 and the foot door 18).

The air conditioner amplifier unit 25 performs arithmetic processing on input signals from switches and sensors according to program software by a built-in microcomputer.
Blower fan motor 5 and each door actuator 21,
2, 23, 24 and a compressor (not shown) are comprehensively controlled.

The water temperature sensor 26 indicates the engine cooling water temperature, the refrigerant temperature sensor 27 indicates the refrigerant temperature, and the inside air sensor 28
Is the inside air temperature TINC, and the outside air sensor 29 is the outside air temperature Tam.
The solar radiation sensor 30 detects the solar radiation amount QSUN, and the suction temperature sensor 31 detects the suction temperature TINT, and inputs them to the air conditioner amplifier unit 25.

The controller 32 is provided on a control panel in the vehicle interior and displays a mode, a fan speed, a temperature, and the like, and an operation unit 32b provided with a mode switch, a temperature adjustment dial, and the like. It is composed of an operation / display / communication circuit 32c for performing display output to the display unit 32a, switch input from the operation unit 32b, and data communication with the air conditioner amplifier unit 25.
The operation / display / communication circuit 32c and the air conditioner amplifier unit 25 are connected by an operation data line 33, a clock signal line 24, and a display communication data line 35.

FIG. 3 is a diagram showing a network between the amplifiers / actuators. The air conditioner amplifier unit 25 and the door actuators 21, 22, 23, 24 are shown in FIG.
As shown in (1), the air conditioner amplifier unit 25 is connected by one communication line 36 and one power line 37, and transmits the addresses of the door actuators 21, 22, 23, 24 and the target position data of the motor. The actuator having the corresponding address receives this data and rotates the motor to the target position.

FIG. 4 is a diagram showing a physical layer (a layer having a function of establishing, maintaining, and canceling the electrical connection of a line in a network) omitting a protection circuit between an amplifier and an actuator. Two types of pulse amplitudes H / L are expressed using a ternary code for superimposing data on a signal. The ASIC of the actuator extracts a clock from the communication signal, and the logic circuit of the ASIC performs decoding of the communication signal (operation for restoring encoded data) and other operations based on the extracted clock. Since the clock signal is supplied only from the amplifier, the communication speed can be arbitrarily set by software of the amplifier.

FIG. 5A is a transmission timing chart showing the transmission operation of the amplifier, and shows the CLK output (clock output).
Is H, Tr1 regardless of DATA output (data output)
The communication line 36 is grounded. When the CLK output is L, the communication line 36 becomes 12 V or an intermediate potential determined by R1 and R2 due to ON / OFF of Tr2 according to the DATA output.

FIG. 5B is a reception timing chart showing the reception operation of the actuator. The data extraction comparator cmp1 has a judgment level larger than the L pulse amplitude, and the clock extraction comparator cmp2 has a judgment level smaller than the L pulse amplitude. have. A signal set by RXDATA and reset at the rising edge of RXCLK is
The decoding is performed by sampling at the falling edge of XCLK. NRZ in the figure is the extracted data.

Next, the operation will be described.

[Communication Procedure] The communication procedure will be described with reference to FIGS.

The signal used for communication defines H / L by two kinds of pulse amplitudes as shown in the communication waveform of FIG. Then, as shown in the encoding table of FIG. 6B, 2-bit binary data is represented by a combination of three pulses.

The communication format is as shown in FIG.
SOM (Start Of Message) indicating the start of transmission, ADR (address) indicating the address of the actuator to be transmitted, ENA (enable) indicating permission or prohibition of motor drive, DATA (data) indicating the target stop position of the door, PRTY (odd parity) for checking ADR, ENA, and DATA errors, and POS (control end signal) representing a diagnostic actuator return signal. FIG. 8 shows an example of the communication format.
It becomes a pulse.

The reception sequence will be described.
Starts the reception sequence by receiving the SOM indicating the start of the communication format. The ASIC fetches the following data only when the corresponding address is detected, but terminates the reception sequence and discards the received data when detecting a combination or a parity error with a waveform that is not in the encoding table. When the SOM is received during the reception sequence, the reception sequence starts over from the beginning. AS
The IC drives the motor only when the enable is 1, and when the enable is 0, only updates the data and does not drive the motor.

Explaining the response from the actuator, the amplifier always turns Tr2 OFF in the POS signal portion,
The two pulses representing the S signal are usually both H pulses. The actuator that receives the signal from the amplifier,
If the door position has reached the target position and the control has been completed,
Tr3 is turned on at a timing such that the second pulse of the POS signal becomes an L pulse. The amplifier can determine whether the door of the actuator to be transmitted is at the target position by monitoring the amplitude of the POS signal. The actuator returns a response only when normal reception is completed, and does not return when an address does not match or an error occurs. FIG. 9A shows the POS signal during the control, and FIG. 9B shows the POS signal at the end of the control.

[Self-diagnosis Operation] FIG. 10 is a time chart showing a check timing of a return signal in the self-diagnosis operation performed by the air conditioner amplifier unit 25 of the first embodiment to determine whether the door actuator control system is normal or abnormal. (Equivalent to the self-diagnosis means in the claims).

First, at the time of self-diagnosis started by a specific operation, if the indicated value to the door actuator is changed, the operation of the door actuator is started at a time t1 delayed from the indicated value changing time t0, and further, the door actuator is operated. At time t2, which is delayed from the start of the operation, the return signal POS switches from Lo indicating stop to Hi indicating operation.

When the operation of the door actuator is completed at time t3, the time t is delayed from the operation end time t3.
At 4, the response signal POS changes from Hi indicating operation to L indicating stop.
Switch to o.

Therefore, a set time (5 to 15 seconds) in consideration of the operation time and the communication delay time from the point of change t0 of the indicated value.
When the return signal is checked at time t5 when the time has elapsed, as long as the door actuator control system is normal, the return signal PO
S becomes Lo indicating stop, and by confirming the return signal POS, it can be determined that the door actuator control system is normal.

On the other hand, when the return signal is checked at a time point t5 when a set time (5 to 15 seconds) has elapsed from the time point t0 at which the indicated value is changed, if the return signal POS is Hi indicating the operation, a communication error is generated. It is determined that the double door actuator control system is abnormal.

[Communication Error Judgment Operation] FIG. 11 is a flowchart showing a flow of a communication error judgment processing operation performed by the air conditioning amplifier unit 25 of the first embodiment due to a ground short. Each step will be described below. (Corresponds to the first communication error determination means in item 1)).

In step 50, communication processing of transmission and reception is performed.

In step 51, it is determined whether the transmission data to be output from the air conditioner amplifier unit 25 is Hi.

In step 52, it is determined whether or not the received data received by the air conditioner amplifier unit 25 is Hi.

In step 53, when YES is determined in steps 51 and 52, it is determined that there is no communication error and the communication is normal.

In step 54, YES in step 51
(Hi), but the step 52
When it is determined YES (Lo) in this case, it is determined that there is an abnormality due to a communication error due to ground short-circuit.

FIG. 12 is a time chart for explaining the determination of a communication error performed in air conditioner amplifier unit 25 of the first embodiment.

First, the transmission data to be output by the air conditioner amplifier unit 25 is data in which the Hi signal and the Lo signal are combined as shown in the upper part of FIG. 12 (FIG. 8).

On the other hand, when the ground is short-circuited, the data transmitted through the communication line 36 is data of only the Lo signal as shown in the middle part of FIG.

Therefore, if the received data (monitor data) received by the air conditioner amplifier unit 25 is a Lo signal when the transmission data is a Hi signal, it can be determined that a communication error has occurred due to a ground short.

That is, when the door actuator control system determines whether the door actuator control system is normal or abnormal based on the self-diagnosis, the return signal POS is always Lo when the ground is short-circuited. An incorrect determination is made. This misjudgment is supplemented by FIGS. 10 and 11.
Is a communication error determination by monitoring the signal levels of the transmission data and the reception data shown in FIG.

Next, the effects will be described.

The air conditioner amplifier unit 25 and the plurality of door actuators 21, 22, 24 are connected to one communication line 36.
And one of the door actuators 21, 22, 24 from the air conditioner amplifier unit 25.
Is transmitted in sequence through one communication line 36, and a return signal POS indicating the operation or stop of each door actuator 21, 22, 24 is added to the transmission data. In the amplifier unit 25, the door target stop position data DATA
Change the indicated value, wait for the delay time, and
S is checked, and if the return signal POS is Lo, it is determined to be normal; if it is Hi, a self-diagnosis program is determined to determine that it is abnormal, and the transmission data to be output by the air conditioner amplifier unit 25 and the reception data received by the In comparison with the data, if the received data corresponding to the Hi signal level in the transmission data is the Lo signal level, a communication error determination program for determining a communication error due to ground short is set. It is possible to provide a communication error determination device that can determine a communication error when the communication line 36 is short-circuited to the ground while reducing the system weight and the system cost.

(Embodiment 2) A communication error determination device according to a second embodiment of the present invention will be described.

The configuration of the vehicle air conditioner system to which the communication error determination device of the second embodiment is applied is the same as that of the first embodiment, so that illustration and description are omitted.

Regarding the operation, the communication procedure and the self-diagnosis operation are the same as those in the first embodiment, and therefore the description is omitted.

[Communication Error Judgment Operation] FIG. 13 is a flowchart showing a flow of a communication error judgment processing operation due to a ground short-circuit performed in the air conditioner amplifier unit 25 of the second embodiment. Each step will be described below. (Corresponds to the second communication error determination means in Item 2).

At step 60, the instruction value sent from the air conditioner amplifier unit 25 to the door actuator is changed.

At step 61, the return signal POS is set to Hi.
It is determined whether or not.

In step 62, the timer value is counted up.

At step 63, it is determined whether the check time has elapsed by comparing the timer value with the set timer value.

In step 64, steps 61 to 63 are repeated. If the check time has elapsed while the return signal POS remains Lo, it is determined that the communication error has occurred due to a ground short.

In step 65, when the reply signal POS becomes Hi in the judgment in step 61, the timer value is cleared.

In step 66, it is determined that there is no communication error and the communication is normal.

FIG. 14 is a time chart illustrating the determination of a communication error performed by air conditioner amplifier unit 25 of the second embodiment.

Checking of the return signal POS is started from the time point t0 when the instruction value from the air conditioner amplifier unit 25 to the door actuator is changed. If there is no communication error and the communication is normal, the time t1 when the delay time has elapsed
, The reply signal POS changes from Lo to Hi.
In the flowchart of FIG.
The flow proceeds from 5 to step 66, and it is determined in step 66 that the state is normal.

On the other hand, when a communication error occurs due to ground short-circuit, the return signal POS is output at time t2 (check time t0 to t2).
Since 2 does not become Hi even after elapse, and remains Lo, in the flowchart of FIG.
The flow from step 62 to step 63 is repeated, and if the time condition of step 63 is satisfied, the process proceeds to step 64. In step 64, it is determined that there is an abnormality due to a communication error due to ground short.

Next, the effects will be described.

In place of the communication error determination program of the first embodiment, the check of the reply signal POS is started from the time point t0 at which the instruction value is changed from the air conditioner amplifier unit 25 to the door actuator. Also, a communication error determination program that determines a communication error due to ground short-circuit is set if it remains Lo and remains Lo, so the LAN between the amplifier and the actuator is set.
Thus, it is possible to provide a communication error determination device capable of determining a communication error when the communication line 36 is short-circuited to the ground while reducing the system weight and the system cost.

In addition, since this communication error determination method is a method of changing an instruction value and monitoring a return signal POS, similarly to the self-diagnosis processing, it can be incorporated in the self-diagnosis processing.

(Other Embodiments) Embodiments 1 and 2
Although the example in which the four door actuators 21, 22, and 24 are provided has been described, it is needless to say that the present invention can be applied to a system in which a plurality of door actuators other than four are provided.

[0075]

According to the first aspect of the present invention, in a vehicle air conditioner system for driving and controlling a plurality of door actuators, an air conditioner amplifier unit and a plurality of door actuators are connected to one communication line and one power supply. Via a communication line, and sequentially sends an instruction value such as door target stop position data from the air conditioner amplifier unit to each door actuator via a single communication line. The transmission data indicates a high or low indicating the operation of each door actuator. The communication format is to add a low return signal indicating stop, change the indicated value from the air conditioner amplifier unit to the door actuator to the air conditioner amplifier unit, wait for the delay time, check the return signal, and if the return signal is low, The self-diagnosis means for determining normal and abnormal if high The first communication error is determined by comparing the received data received by the air conditioner amplifier unit with the transmitted data, and if the received data corresponding to the high signal level in the transmitted data is the low signal level, it is determined that a communication error has occurred due to ground short-circuit. Since the means is provided, it is possible to provide a communication error determination device capable of determining a communication error when a communication line is short-circuited to ground while reducing the system weight and system cost by using a LAN between the amplifier and the actuator. The effect is obtained.

According to the second aspect of the present invention, a first aspect is provided.
In the communication error determination device for a vehicle air conditioner system described above, instead of the first communication error determination means, the air conditioner amplifier unit starts checking the return signal from the point of time when the indicated value is changed from the air conditioner amplifier unit to the door actuator, and returns The second communication error determination means for determining a communication error due to ground short if the signal does not become high even if the signal has passed the set time and remains low when the signal is low is provided. The effect of being able to provide a communication error determination device capable of determining a communication error when the communication line is short-circuited to the ground while reducing the system cost is obtained.

[Brief description of the drawings]

FIG. 1 is a claim correspondence diagram showing a communication error determination device of a vehicle air conditioner system of the present invention.

FIG. 2 is an overall view of a vehicle air conditioner system to which the communication error determination device according to the first embodiment is applied.

FIG. 3 is a diagram illustrating a network between an amplifier and an actuator according to the first embodiment;

FIG. 4 is a diagram illustrating a physical layer in which a protection circuit between an amplifier and an actuator according to the first embodiment is omitted.

FIG. 5A is a transmission timing chart showing a transmission operation of the amplifier, and FIG. 5B is a reception timing chart showing a reception operation of the actuator.

FIG. 6 (a) is a diagram showing a communication waveform, and FIG.
FIG. 4 is a diagram showing an encoding table.

FIG. 7 is a diagram showing a communication format used for data communication.

FIG. 8 is a diagram illustrating an example of a communication format.

FIG. 9A shows a POS signal under control, and FIG.
(B) shows the POS signal at the end of the control.

FIG. 10 is a time chart showing a check timing of a return signal in a self-diagnosis operation for determining whether a door actuator control system is normal or abnormal in the air conditioner amplifier unit according to the first embodiment.

FIG. 11 is a flowchart showing a flow of a communication error determination processing operation performed by the air conditioning amplifier unit according to the first embodiment due to a ground short.

FIG. 12 is a time chart illustrating a communication error determination performed by the air conditioner amplifier unit according to the first embodiment;

FIG. 13 is a flowchart showing a flow of a communication error determination processing operation due to a ground short-circuit performed in the air conditioner amplifier unit of the second embodiment.

FIG. 14 is a time chart illustrating a determination of a communication error performed in the air conditioner amplifier unit according to the second embodiment.

[Explanation of symbols]

 a operation unit b controller c fan motor d, e, f door actuator g air conditioner amplifier unit h communication line i power line j self-diagnosis means k first communication error determination means m second communication error determination means

Claims (2)

[Claims] 1. A controller having an operation unit provided with switches such as a mode switch and a temperature adjustment dial, and a built-in microcomputer which performs an arithmetic process on input signals from the switches and sensors according to program software. An air conditioning system for a vehicle including an air conditioner amplifier unit for driving and controlling a fan motor and a plurality of door actuators provided in an air conditioning system, wherein the air conditioner amplifier unit and the plurality of door actuators are connected to one communication line and one The air conditioner amplifier unit is connected to each door actuator, and an instruction value such as door target stop position data is sequentially transmitted through one communication line from the air conditioner amplifier unit to the door actuator. Communication signal to add a high return signal indicating In the air conditioner amplifier unit, change the indicated value from the air conditioner amplifier unit to the door actuator, check the return signal after waiting for a delay time, determine that the return signal is low if it is normal, and if it is high it is abnormal. Self-diagnosis means for determining that the transmission data that the air conditioning amplifier unit wants to output and the reception data that the air conditioning amplifier unit has received,
A communication error determination for a vehicle air-conditioning system, comprising first communication error determination means for determining a communication error due to ground short if reception data corresponding to a high signal level in transmission data is a low signal level. apparatus. 2. The communication error determination device for an air conditioner system for a vehicle according to claim 1, wherein said first communication error determination means is replaced with said air conditioner amplifier unit, and a point of time when an indicated value is changed from an air conditioner amplifier unit to a door actuator. And a second communication error determining means for determining that a communication error has occurred due to a ground short if the response signal does not become high even if the set time has elapsed and remains low when the response signal has elapsed. Communication error determination device for a vehicle air conditioner system.