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DTC Troubleshooting

DTC TROUBLESHOOTING CHART

Step Action YES NO
1  Was "Electronic Stability Program Check" performed?  Go to Step 2. Go to ELECTRONIC STABILITY PROGRAM CHECK .
2  DTC check for ESP® 
  1. Check DTC for ESP®.

Is DTC U1139 and DTC U1073 detected together? 		 Go to DTC U1073: CONTROL MODULE COMMUNICATION BUS OFF  for troubleshooting. Go to Step 3.
3  DTC check for 4WD control module 
  1. Check DTC for 4WD control module.

Is DTC P1073 detected? 		 Go to DTC U1073: CONTROL MODULE COMMUNICATION BUS OFF :Motor-Shift Type (Transfer with Shift Actuator)  for troubleshooting. Go to Step 4.
4  Check each control module connectors 
  1. Check connection of connectors of all control modules communicating by means of CAN.
  2. Check DTC for ESP®.

Is DTC U1139 detected? 		 Go to Step 4. Check for intermittent trouble referring to INTERMITTENT AND POOR CONNECTION INSPECTION .
5  CAN communication circuit check 
  1. Turn ignition switch to OFF position.
  2. Disconnect connectors of ESP® control module and 4WD control module communicating by means of CAN.

Is each CAN communication circuit between ESP® control module and 4WD control module opened, shorted or high resistance? 		 Repair or replace the CAN communication line. Go to Step 6.
6  DTC check for ESP® 
  1. Turn ignition switch to OFF position.
  2. Disconnect connectors of all control modules communicating by means of CAN.
  3. Connect connectors to ESP® control module and 4WD control module.
  4. Check DTC for ESP®.

Is DTC U1139 detected? 		 Go to Step 7. Go to Step 8.
7  Check 4WD control module 
  1. Turn ignition switch to OFF position.
  2. Check 4WD control module power and ground circuit.
  3. If OK, then substitute a known-good 4WD control module.
  4. Connect connectors of disconnected control modules communicating by means of CAN.
  5. Clear all DTC(s) and check DTC for ESP®.

Is DTC U1139 detected? 		 Check ESP® power and ground circuit. If circuit is OK, substitute a known-good ESP® hydraulic unit/control module assembly and check DTC. 4WD control module was malfunction.
8  CAN communication circuit check 
  1. Turn ignition switch to OFF position.

Is each CAN communication circuit between disconnected control modules (other than ESP® control module and 4WD control module) opened, shorted or high resistance? 		 Repair or replace the CAN communication line. Go to Step 9.
9  DTC check for ESP® 
  1. Connect connectors of disconnected control modules communicating by means of CAN.
  2. Disconnect each connector.
    • ECM
    • TCM (for A/T model)
    • BCM
    • 4WD control module
    • Keyless start control module (if equipped)
    • Steering angle sensor
  3. Check DTC for ESP®.

Is DTC U1139 detected? 		 Check ESP® control module power and ground circuit. If circuits are OK, substitute a known-good ESP® hydraulic unit/control module assembly and check DTC. Check applicable control module power and ground circuit. If circuit is OK, substitute a known-good applicable control module and check DTC.
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