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DTC Troubleshooting

NOTE: Before this trouble shooting is performed, read the precautions for DTC troubleshooting referring to PRECAUTIONS FOR DTC TROUBLESHOOTING .
DTC TROUBLESHOOTING CHART

Step Action YES NO
1  Was "Engine and Emission Control System Check" performed?  Go to Step 2. Go to ENGINE AND EMISSION CONTROL SYSTEM CHECK .
2  DTC check 
  1. Connect scan tool to DLC with ignition switch turned OFF.
  2. Check for all control modules (ECM, TCM (if equipped), BCM, ABS or ESP® control module, 4WD control module (if equipped), keyless start control module (if equipped), combination meter, steering angle sensor (if equipped) for DTC(s) other than CAN communication DTCs.

Is there any DTC(s) other than CAN communication DTC(s) at each control module (other than DTC U0073, U0100, U0101, U0121, U0140, U1073, U1100, U1101, U1121, U1126, U1139, U1140, U1144)? 		 Go to applicable DTC diagnostic flow chart. Go to Step 3.
3  DTC check 
Is DTC U0140 and U0073 detected together? 		 Go to DTC U0073: CONTROL MODULE COMMUNICATION BUS OFF . Go to Step 4.
4  ECM, ABS ESP® control module and BCM connector check 
  1. Check for proper connection at each ECM, ABS or ESP® control module and BCM connector terminals with ignition switch turned OFF.
  2. If connections are OK, recheck ECM for DTC with engine running.

Is there DTC U0140? 		 Go to Step 5. Intermittent trouble. Check for intermittent referring to INTERMITTENT AND POOR CONNECTION INSPECTION .
5  ECM power and ground circuit check 
  1. Check ECM power and ground circuits referring to ECM POWER AND GROUND CIRCUIT CHECK .

Are they in good condition? 		 Go to Step 6. Repair ECM power and/or ground circuits.
6  DTC check in BCM 
  1. Check DTC U1073 in BCM.

Is it indicated? 		 Go to DTC U1073 (NO. 1073): CONTROL MODULE COMMUNICATION BUS OFF . Go to Step 7.
7  DTC check 
  1. Disconnect connector from BCM and ECM.
  2. Check that CAN communication circuit is as follows.
    • Circuit resistance of CAN communication circuit is less than 1 Ω between ECM connector and BCM connector.

Is it in good condition? 		 Go to Step 9. Go to Step 8.
8  ABS or ESP® control module check 
  1. Measure resistance at following connector terminals.
    • Between "WHT/BLU" terminal and "WHT" terminal of ABS or ESP® control module connector.
    • Between "WHT/RED" terminal and "RED" terminal of ABS or ESP® control module connector.

Is measured resistance below 1 Ω? 		 CAN communication circuit wire between BCM and ECM connector is open or high resistance. Substitute a known-good ABS or ESP® control module and recheck.
9  DTC check 
  1. Connect connectors to BCM and ECM with ignition switch turned OFF.
  2. Disconnect connectors from TCM (for A/T model) with ignition switch turned OFF.
  3. Check ECM for DTC.

Is there DTC U0140? 		 Go to Step 9. CAN communication circuit wire between TCM and CAN circuit junction connector is open or high resistance. If wires are OK, check TCM power and ground circuits. If circuits are OK, substitute a known-good TCM (for A/T model) and recheck.
10  DTC check 
  1. Disconnect connector from keyless start control module (if equipped) with ignition switch turned OFF.
  2. Check ECM for DTC.

Is there DTC U0140? 		 Go to Step 10. CAN communication circuit wire between keyless start control module and CAN circuit junction connector is open or high resistance. If wires are OK, check keyless start control module power and ground circuits. If circuits are OK, substitute a known-good keyless start control module and recheck.
11  DTC check 
  1. Disconnect connector from combination meter with ignition switch turned OFF.
  2. Check ECM for DTC.

Is there DTC U0140? 		 Go to Step 11. CAN communication circuit wire between combination meter and CAN circuit junction connector is open or high resistance. If wires are OK, check combination meter power and ground circuits. If circuits are OK, substitute a known-good combination meter and recheck.
12  DTC check 
  1. Disconnect connector from 4WD control module (if equipped) with ignition switch turned OFF.
  2. Check ECM for DTC.

Is there DTC U0140? 		 Go to Step 12. CAN communication circuit wire between 4WD control module and CAN circuit junction connector is open or high resistance. If wires are OK, check 4WD control module power and ground circuits. If circuits are OK, substitute a known-good 4WD control module and recheck.
13  DTC check 
  1. Disconnect connector from steering angle sensor (if equipped ESP®) with ignition switch turned OFF.
  2. Check ECM for DTC.

Is there DTC U0140? 		 Go to Step 14. CAN communication circuit wire between steering angle sensor and CAN circuit junction connector is open or high resistance. If wires are OK, check steering angle sensor power and ground circuits. If circuits are OK, substitute a known-good steering angle sensor and recheck.
14  DTC check 
  1. Disconnect connectors from all control modules (ECM, TCM (if equipped), BCM, ABS or ESP® control module, 4WD control module (if equipped), keyless start control module (if equipped), combination meter, steering angle sensor (if equipped) with ignition switch turned OFF.
  2. Check that CAN communication circuit is as follows.
    • ALL wire harness resistance of CAN communication circuit is less than 1 Ω between each control module.
    • Insulation resistance between CAN communication circuit wires is infinity at each control module connector.
    • Insulation resistance between each CAN communication circuit wire and vehicle body ground is infinity at each control module connector.
    • Circuit voltage of CAN communication circuit is 0 V with ignition switch turned ON.

Are they in good condition? 		 Go to Step 15. Repair or replace defective CAN communication circuit.
15  Vehicle spec check 
Is vehicle equipped with A/T? 		 Go to Step 16. Go to Step 17.
16  DTC check in TCM (for A/T model) 
  1. Connect connectors to all control modules with ignition switch turned OFF.
  2. Check DTC U0140 in TCM (for A/T model).

Is it indicated? 		 Go to Step 17. Substitute a known-good ECM and recheck.
17  Combination meter operation check 
  1. Check combination meter operation for seat belt warning lamp by fastening and unfastening driver side seat belt with ignition switch turned ON.

Is it check result satisfactory? 		 Substitute a known-good ECM and recheck. Check BCM power and ground circuits, If circuits are OK, substitute a known-good BCM and recheck.
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