Component Tests and General Diagnostics

ATP SWITCH


Description

The ATP indicator is ON when the transfer case is not in neutral.





ATP SWITCH


Diagnosis Procedure

Regarding Wiring Diagram information, [1][2]Electrical Diagrams.
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.






Are inspection results normal?
YES - GO TO 5.
NO - 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 E143 terminal 40 and ATP switch harness connector F55 terminal 8.

Continuity should exist.

Also check harness for short to ground and short to power.
Are inspection results normal?
YES - GO TO 3.
NO - 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 ground and short to power.
Are inspection results normal?
YES - GO TO 4.
NO - Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK ATP SWITCH
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect ATP switch harness connector.
3. Remove ATP switch. Locations.





4. Push and release ATP switch and check continuity between ATP switch terminals 8 and 9.






Are inspection results normal?
YES - GO TO 5.
NO - Replace ATP switch.
5.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Pinout Values and Diagnostic Parameters.
Are inspection results normal?
YES - GO TO 6.
NO - 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. Move A/T selector lever to P position.
3. Set 4WD shift switch from 4H to 4LO or 4LO to 4H.
Does ATP warning lamp turn ON while switching?
YES - Inspection End.
NO - GO TO ATP Warning Lamp Does Not Turn ON.