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

1.CHECK SYSTEM FOR CAN COMMUNICATION LINE
Perform self-diagnosis. Refer to Scan Tool Testing and Procedures.
Do the self-diagnostic results indicate CAN communication?
YES - Perform trouble diagnosis for CAN communication line. Refer to Testing and Inspection.
NO - GO TO 2.
2.CHECK SYSTEM FOR 4WD SHIFT SWITCH
Perform trouble diagnosis for 4WD shift switch system. Refer to P1813.
Are the inspection results normal?
YES - GO TO 3.
NO - Repair or replace damaged parts.
3.CHECK SYSTEM FOR PNP SWITCH SIGNAL
Perform trouble diagnosis for PNP switch signal system. Refer to PNP Switch (A/T).
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. Refer to Diagnosis Procedure.
Are the inspection results normal?
YES - GO TO 5.
NO - Repair or replace damaged parts.
5.CHECK ATP WARNING LAMP CIRCUIT
1. Disconnect ATP switch harness connector.
2. Turn ignition switch "ON". (Do not start engine.)





3. Ground terminal 8 on ATP switch connector F55 using suitable wiring.
4. Turn ignition switch "OFF". (Stay for at least 5 seconds.)
Does ATP warning lamp turn on?
YES - GO TO 9.
NO - GO TO 6.
6.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 transfer control unit harness connector M153 terminal 39 and combination meter harness connector M24 terminal 21.

Continuity should exist.

Also check harness for short to ground and short to power.
Does continuity exist?
YES - GO TO 7.
NO - Repair or replace damaged parts.
7.CHECK HARNESS BETWEEN COMBINATION METER AND ATP SWITCH
1. Turn ignition switch "OFF". (Stay for at least 5 seconds.)
2. Disconnect ATP switch harness connector.





3. Check continuity between combination meter harness connector M24 terminal 1 and ATP switch harness connector F55 terminal 8.

Continuity should exist.

Also check harness for short to ground and short to power.
Does continuity exist?
YES - GO TO 8.
NO - Repair or replace damaged parts.
8.SYMPTOM CHECK
Check again.
Does the symptom still occur?
YES - GO TO 9.
NO - Inspection End.
9.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to Pinout Values and Diagnostic Parameters.
Are the inspection results normal?
YES - GO TO 10.
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.
10.CHECK TRANSFER INNER PARTS
1. Disassemble transfer assembly. Refer to Disassembly And Assembly.
2. Check transfer inner parts.
Are the inspection results normal?
YES - Inspection End.
NO - Repair or replace damaged parts.