Rear Air Control Rear Diagnosis Procedure
REAR AIR CONTROL SYSTEM
Rear Air Control (Rear) Diagnosis Procedure
Regarding Wiring Diagram information, Automatic Air Conditioning.
1. CHECK REAR AIR CONTROL (FRONT) REAR CONTROL SELECT SWITCH
Did the REAR CTRL lamp illuminate when selected?
Is the inspection result normal?
YES- GO TO 2.
NO- GO TO 3.
2. CHECK AIR MIX DOOR MOTOR (REAR) POSITION BALANCED RESISTOR (PBR) FEEDBACK VOLT-
AGE
1.Turn ignition switch ON.
2.Using CONSULT, check "RR FDBCK" in "DATA MONITOR" mode in "HVAC". CONSULT Function (HVAC).
3.Observe "RR FDBCK" voltage while rotating rear temperature control dial (rear) between 32�C (90�F) and
18�C (60�F).
Is the inspection result normal?
YES- - Air mix door motor (rear) is OK.
- Inspect air mix door (rear) for mechanical failure and repair if necessary.
NO- GO TO 12.
3. CHECK REAR AIR CONTROL (REAR) GROUND CIRCUIT
1.Turn ignition switch OFF.
2.Check continuity between rear air control (rear) harness connector M208 terminal 1 and ground.
Continuity should exist.
Is the inspection result normal?
YES- GO TO 4.
NO- Repair harness or connector.
4. CHECK REAR AIR CONTROL (FRONT) REAR CONTROL TELLTALE SIGNAL
While repeatedly pressing and releasing the rear air control (front) rear control select switch, check voltage between rear air control (front) harness connector R2 terminal 4 and ground.
Is the inspection result normal?
YES- Replace rear air control (front). Service and Repair.
NO- GO TO 5.
5. CHECK REAR AIR CONTROL (FRONT) REAR CONTROL SELECT SWITCH SIGNAL
While pressing and holding the rear air control (front) rear control select switch, check voltage between rear air control (front) harness connector R2 terminal 5 and ground.
Is the inspection result normal?
YES- GO TO 8.
NO- GO TO 6.
6. CHECK REAR AIR CONTROL (FRONT) REAR CONTROL SELECT SWITCH SIGNAL
1.Turn ignition switch OFF.
2.Disconnect A/C auto amp connector (M50).
3.Turn ignition switch ON.
4.While pressing and holding the rear air control (front) rear control select switch, check voltage between rear air control (front) harness connector R2 terminal 5 and ground.
Is the inspection result normal?
YES- Replace A/C auto amp. Service and Repair.
NO- GO TO 7.
7. CHECK REAR AIR CONTROL (FRONT) REAR CONTROL SELECT SWITCH CIRCUIT
1.Turn ignition switch OFF.
2.Disconnect rear air control (front) connector.
3.Check continuity between A/C auto amp. harness connector M50 terminal 39 and rear air control (front)
harness connector R2 terminal 5.
Continuity should exist.
4.Check continuity between A/C auto amp. harness connector M50 terminal 39 ground.
Continuity should not exist.
Is the inspection result normal?
YES- Replace rear air control (front). Service and Repair.
NO- Repair harness or connector.
8. CHECK REAR AIR CONTROL (FRONT) REAR CONTROL SELECT SWITCH SIGNAL
While pressing and holding the rear air control (front) rear control select switch, check voltage between A/C
auto amp. harness connector M50 terminal 39 and ground.
Is the inspection result normal?
YES- GO TO 9.
NO- Repair harness or connector.
9. CHECK REAR AIR CONTROL (FRONT) REAR CONTROL TELLTALE SIGNAL
Repeatedly press and release the rear air control (front) rear control select switch and check voltage between
A/C auto amp. harness connector M50 terminal 35 and ground.
Is the inspection result normal?
YES- Repair harness or connector.
NO- GO TO 10.
10. CHECK REAR AIR CONTROL (FRONT) REAR CONTROL TELLTALE CIRCUIT
1.Turn ignition switch OFF.
2.Disconnect A/C auto amp connector M50 and rear air control (front) connector R2.
3.Check continuity between A/C auto amp. harness connector M50 terminal 35 and rear air control (front)
harness connector R2 terminal 4.
Continuity should exist.
4.Check continuity between A/C auto amp. harness connector M50 terminal 35 and ground.
Continuity should not exist.
Is the inspection result normal?
YES- GO TO 11.
NO- Repair harness or connector.
11. CHECK REAR AIR CONTROL (FRONT) REAR CONTROL TELLTALE CIRCUIT
1.Reconnect rear air control (front) connector.
2.Check continuity between rear air control (front) connector R2 terminal 4 and ground.
Continuity should not exist.
Is the inspection result normal?
YES- Replace A/C auto amp. Service and Repair.
NO- Replace rear air control (front). Service and Repair.
12. CHECK REAR AIR CONTROL (REAR) GROUND CIRCUIT
1.Turn ignition switch OFF.
2.Check continuity between rear air control (rear) harness connector M208 terminal 1 and ground.
Continuity should exist.
Is the inspection result normal?
YES- GO TO 13.
NO- Repair harness or connector.
13. CHECK REAR AIR CONTROL (REAR) REFERENCE VOLTAGE
1.Turn ignition switch ON.
2.Check voltage between rear air control (rear) harness connector M208 terminal 3 and ground.
Is the inspection result normal?
YES- GO TO 15.
NO- GO TO 14.
14. CHECK REAR AIR CONTROL (REAR) REFERENCE VOLTAGE CIRCUIT
1.Disconnect A/C auto amp. connector.
2.Check continuity between A/C auto amp. harness connector M50 terminal 28 and rear air control (rear)
harness connector M208 terminal 3.
Continuity should exist.
Is the inspection result normal?
YES- Replace A/C auto amp. Service and Repair.
NO- Repair harness or connector.
15. CHECK REAR AIR CONTROL (REAR) REFERENCE GROUND CIRCUIT
1.Turn ignition switch OFF.
2.Check continuity between rear air control (rear) harness connector M208 terminal 8 and ground.
Continuity should exist.
Is the inspection result normal?
YES- GO TO 17
NO- GO TO 18.
16. CHECK REAR AIR CONTROL (REAR) REFERENCE GROUND CIRCUIT FOR OPEN
1.Disconnect A/C auto amp. connector and rear air control (rear) harness connector.
2.Check continuity between A/C auto amp. harness connector M49 terminal 3 and rear air control (rear) harness connector M208 terminal 8.
Continuity should exist.
Is the inspection result normal?
YES- Replace A/C auto amp. Service and Repair.
NO- Repair harness or connector.
17. CHECK REAR AIR CONTROL (REAR) AUX TEMP POT VOLTAGE
1.Turn ignition ON.
2.Check voltage between rear air control (rear) harness connector M208 terminal 7 and ground while turning knob between full cold and full hot.
Is the inspection result normal?
YES- GO TO 19.
NO- GO TO 18.
18. CHECK REAR AIR CONTROL (REAR) AUX TEMP POT CIRCUIT
1.Turn ignition switch OFF.
2.Disconnect A/C auto amp. connector and rear air control (rear) connector.
3.Check continuity between A/C auto amp. harness connector M50 terminal 51 and rear air control (rear)
harness connector M208 terminal 7.
Continuity should exist.
4.Check continuity between A/C auto amp. harness connector M50 terminal 51 and ground.
Continuity should not exist.
Is the inspection result normal?
YES- Replace rear air control (rear) switch. Service and Repair.
NO- Repair harness or connector.
19. CHECK REAR AIR CONTROL (REAR) AUX TEMP POT VOLTAGE
Check voltage between A/C auto amp. harness connector M50 terminal 51 and ground while turning knob between full cold and full hot.
Is the inspection result normal?
YES- GO TO 21.
NO- GO TO 20.
20. CHECK REAR AIR CONTROL (REAR) AUX TEMP POT CIRCUIT
1.Turn ignition switch OFF.
2.Disconnect A/C auto amp. connector and rear air control (rear) connector.
3.Check continuity between A/C auto amp. harness connector M50 terminal 51 and rear air control (rear)
harness connector M208 terminal 7.
Continuity should exist.
Is the inspection result normal?
YES- Replace A/C auto amp. Service and Repair.
NO- Repair harness or connector.
21. CHECK AIR MIX DOOR MOTOR (REAR) CIRCUITS FOR OPEN AND SHORT TO GROUND
1.Turn ignition switch OFF.
2.Disconnect the A/C auto amp. harness connector M50 and the air mix door motor (rear) harness connector B155.
3.Check continuity between A/C auto amp. harness connector M50 terminals 43, 44 and the air mix door motor (rear) harness connector B155 terminal 1, 6.
4.Check continuity between A/C auto amp. harness connector M50 terminals 43, 44 and ground.
Is the inspection result normal?
YES- GO TO 22.
NO- Repair or replace harness as necessary.
22. CHECK A/C AUTO AMP. FOR AIR MIX DOOR MOTOR (REAR) POWER AND GROUND
1.Reconnect A/C auto amp. harness connector.
2.Turn ignition switch ON.
3.Rotate temperature control dial (rear) to maximum hot.
4.Check voltage between A/C auto amp. harness connector M50 terminal 43 and terminal 44 while rotating temperature control dial (rear) to maximum cold and back to maximum heat.
Is the inspection result normal?
YES- GO TO 23.
NO- Replace A/C auto amp. Service and Repair.
23. CHECK AIR MIX DOOR MOTOR (REAR) PBR CIRCUITS FOR OPEN AND SHORT TO GROUND
1.Turn ignition switch OFF.
2.Disconnect the A/C auto amp. harness connectors M49 and M50.
3.Check continuity between A/C auto amp. harness connector M49 terminal 3 and M50 terminal 28 and air mix door motor (rear) harness connector B155 terminal 2, 3.
4.Check continuity between A/C auto amp. harness connector M49 terminal 3, M50 terminal 28 and ground.
Is the inspection result normal?
YES- GO TO 24.
NO- Repair or replace harness as necessary.
24. CHECK PBR FEEDBACK SIGNAL CIRCUIT FOR OPEN AND SHORT TO GROUND
1.Check continuity between A/C auto amp. harness connector M50 terminal 30 and air mix door motor (rear) harness connector B155 terminal 4.
2.Check continuity between A/C auto amp. harness connector M50 terminal 30 and ground.
Is the inspection result normal?
YES- GO TO 25.
NO- Repair or replace harness as necessary.
25. CHECK A/C AUTO AMP. FOR 5 VOLT REFERENCE (VREF), VREF RETURN, AND FEEDBACK SIGNAL
1.Reconnect A/C auto amp. harness connectors.
2.Turn ignition switch ON.
3.Check voltage between A/C auto amp. harness connector M49 terminal 3, and M50 terminal 28.
4.Check voltage between A/C auto amp. harness connector M50 terminal 30 and ground.
Is the inspection result normal?
YES- GO TO 26.
NO- Replace A/C auto amp. Service and Repair.
26. CHECK A/C AUTO AMP. FOR FEEDBACK SIGNAL
1.Reconnect the air mix door motor (rear) harness connector B155.
2.Check voltage between A/C auto amp. harness connector M50 terminal 30 and ground.
Is the inspection result normal?
YES- Inspect air mix door (rear) for binding or mechanical failure. If air mix door (rear) moves freely, replace A/C auto amp. Service and Repair.
NO- Replace the air mix door motor (rear). Removal And Installation.