ATP Switch

ATP SWITCH

Description
The ATP indicator does not come on when the transfer is in neutral and the A/T lever is in neutral or, the ATP indicator stays on when the transfer case is not in neutral.

Diagnosis Procedure

DIAGNOSTIC PROCEDURE

1. CHECK ATP SWITCH SIGNAL

With CONSULT-III
1. Start engine.
2. Select DATA MONITOR mode for ALL MODE AWD/4WD with CONSULT-III.
3. Read out the value of ATP SWITCH.





Without CONSULT-III
1. Start engine.








2. Check voltage between transfer control unit harness connector terminal and ground.
OK or NG
OK >> GO TO 5.
NG >> GO TO 2.

2. CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND ATP SWITCH
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and the ATP switch harness connector.





3. Check continuity between transfer control unit harness connector E142 terminal 23 and ATP switch harness connector F55 terminal 8.
Continuity should exist.
Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.

3. CHECK GROUND CIRCUIT
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect ATP switch harness connector.





3. Check continuity between ATP switch harness connector F55 terminal 9 and ground.
Continuity should exist.
Also check harness for short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to power in harness or connectors.

4. CHECK ATP SWITCH
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Remove ATP switch.








3. Push and release ATP switch and check continuity between ATP switch terminals 8 and 9.
OK or NG
OK >> GO TO 5.
NG >> Replace ATP switch.

5. CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to DLN-50, "Reference Value". Reference Value
OK or NG
OK >> GO TO 6.
NG >> Check transfer control unit pin terminals for damage or loose connection with harness connector. If any items are damaged, repair or replace damaged parts.

6. CHECK ATP WARNING LAMP
1. Turn ignition switch ON. (Do not start engine.)
2. A/T selector lever N position and engage the parking brake.
3. Switch 4WD shift switch from 4H to 4LO or 4LO to 4H.
Does ATP warning lamp ON, while actuator motor is operating?
YES >> Inspection End.
NO >> Refer to DLN-71, "Diagnosis Procedure". 4WD Warning Lamp Does Not Turn on

Component Inspection
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect ATP switch harness connector.
3. Remove ATP switch.








4. Push and release ATP switch and check continuity between ATP switch terminals 8 and 9.
5. If the inspection results are abnormal replace the ATP switch.