ATP Warning Lamp Does Not Turn ON

ATP WARNING LAMP DOES NOT TURN ON


Description

ATP warning lamp does not turn ON when the transfer case is switched in or out of 4LO with the A/T selector lever in N position.





ATP WARNING LAMP DOES NOT TURN ON


Diagnosis Procedure

Regarding Wiring Diagram information, [1][2]Electrical Diagrams.
1.CHECK SYSTEM FOR CAN COMMUNICATION LINE
Perform self-diagnosis. Scan Tool Testing and Procedures.
Do the self-diagnostic results indicate CAN communication?
YES - Perform trouble diagnosis for CAN communication line.
NO - GO TO 2.
2.CHECK SYSTEM FOR 4WD SHIFT SWITCH
Perform trouble diagnosis for 4WD shift switch system. P1813.
Are the inspection results normal?
YES - GO TO 3.
NO - Repair or replace damaged parts.
3.CHECK SYSTEM FOR TRANSMISSION RANGE SWITCH SIGNAL
Perform trouble diagnosis for transmission range switch signal system. P1816.
Are the inspection results normal?
YES - GO TO 4.
NO - Repair or replace damaged parts.
4.CHECK SYSTEM FOR ATP SWITCH
Perform trouble diagnosis for ATP switch system. Component Tests and General Diagnostics.
Are the inspection results normal?
YES - GO TO 5.
NO - Repair or replace damaged parts.
5.CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND COMBINATION METER
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and combination meter harness connector.
3. Check continuity between the following terminals.





- Transfer control unit harness connector E142 terminal 15 and combination meter harness connector M24 terminal 6.

Continuity should exist.






- Transfer control unit harness connector E143 terminal 40 and combination meter harness connector M24 terminal 7.






Also check harness for short to ground and short to power.
Are the inspection results normal?
YES - GO TO 6.
NO - Repair or replace damaged parts.
6.CHECK ATP WARNING LAMP CIRCUIT
1. Place A/T selector lever in in P position.
2. Connect combination meter harness connector and transfer control unit harness connector.
3. Disconnect ATP switch harness connector.





4. Ground the following terminal using suitable wiring.
- ATP switch harness connector F55 terminal 8 and ground.
5. Turn ignition switch ON. (Do not start engine.)
Does indicator lamp turn on?
YES - GO TO 7.
NO - Replace combination meter. Refer to Service and Repair.
7.SYMPTOM CHECK
Check again.
Are the inspection results normal?
YES - Inspection End.
NO - GO TO 8.
8.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Pinout Values and Diagnostic Parameters.
Are the inspection results normal?
YES - GO TO 9.
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.
9.CHECK TRANSFER INNER PARTS
1. Disassemble transfer assembly. Overhaul.
2. Check transfer inner parts.
Are the inspection results normal?
YES - Inspection End.
NO - Repair or replace damaged parts.