Air Conditioning System

AIR CONDITIONING: AIR CONDITIONING SYSTEM: 31: Air Mix Damper Position Sensor Circuit (Passenger Side)

DTC 31 - Air Mix Damper Position Sensor Circuit (Passenger Side)

DESCRIPTION

This sensor detects the position of the air mix damper and sends the appropriate signals to the A/C amplifier. The position sensor is built into the damper servo sub-assembly (air mix control servo motor).









WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT AIR CONDITIONING AMPLIFIER (TPP, SG)




(a) Remove the A/C amplifier with the connectors still connected.
(b) Turn the ignition switch ON.
(c) Change the set temperature to activate the air mix damper.
(d) Measure the voltage according to the value(s) in the table below.
Standard voltage:





HINT: As the set temperature increases, the voltage decreases gradually without interruption.

Result:






C -- REPLACE AIR CONDITIONING AMPLIFIER
B -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
A -- Continue to next step.
2. INSPECT DAMPER SERVO SUB-ASSEMBLY
(a) Remove the damper servo sub-assembly.




(b) Disconnect the connector from the damper servo sub-assembly.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:









(d) Measure the resistance according to the value(s) in the table below.
Standard resistance:









(e) As the damper servo sub-assembly moves from COLD side to HOT side, the resistance decreases gradually without interruption.
HINT: For details regarding operation of the servo motor [1][2]Air Conditioning System.

NG -- REPLACE DAMPER SERVO SUB-ASSEMBLY
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (AIR MIX DAMPER POSITION SENSOR - A/C AMPLIFIER)
(a) Check for open and short in the harness and the connector between the damper servo sub-assembly (air mix damper position sensor) and the A/C amplifier Electronic Circuit Inspection Procedure.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. CHECK DTC
(a) Start up the DTC check mode.
(b) Check that DTC 31 is not output again.
Result:






B -- SYSTEM IS OK
A -- REPLACE AIR CONDITIONING AMPLIFIER