DLC Circuit Troubleshooting (F-CAN, IMA-CAN, K-LINE)
DLC Circuit Troubleshooting
NOTE: If you suspect the HDS or the HDS DLC cable may be the source of the communication problem, verify that they are working properly by connecting them to a known-good, like vehicle and system, and checking for communication problems.
1. Turn the ignition switch to LOCK (0).
2. Connect the HDS to the DLC.
3. Turn the ignition switch to ON (II), and read the HDS.
Does the HDS identify the vehicle?
YES -
Go to step 5.
NO -
Go to step 4.
4. Try to start the engine.
Does the engine start and idle smoothly?
YES -
Go to step 24.
NO -
Go to the ECM/PCM power and ground circuit troubleshooting ECM/PCM Power and Ground Circuit Troubleshooting.
5. Check for Pending or Confirmed DTCs in the PGM-FI system with the HDS.
Are any Pending or Confirmed DTCs indicated?
YES -
Go to the indicated DTC's troubleshooting.
NO -
- If the HDS does not communicate with the SRS, go to step 6.
- If the HDS does not communicate with the VSA system, go to step 8.
- If the HDS does not communicate with the EPS system, go to step 10.
- If the HDS does not communicate with the TPMS, go to step 12.
- If the HDS does not communicate with the IMMOBI (immobilizer) system, go to step 14.
- If the HDS does not communicate with the BODY ELECTRICAL system, go to step 16.
6. Turn the ignition switch to LOCK (0).
7. Turn the ignition switch to ON (II), and watch the SRS indicator.
Does the SRS indicator come on and go off?
YES -
Go to step 18.
NO -
Go to the SRS general troubleshooting information Reading and Clearing Diagnostic Trouble Codes.
8. Turn the ignition switch to LOCK (0).
9. Turn the ignition switch to ON (II), and watch the VSA indicator.
Does the VSA indicator come on and go off?
YES -
Go to step 18.
NO -
Go to the VSA symptom troubleshooting for ABS indicator, brake system indicator, and VSA indicator do not go off Symptom Troubleshooting.
10. Turn the ignition switch to LOCK (0).
11. Start the engine, and watch the EPS indicator.
Does the EPS indicator come on and go off?
YES -
Go to step 18.
NO -
Go to the EPS symptom troubleshooting for EPS indicator does not go off, and no DTCs are stored EPS Indicator Does Not Come On.
12. Turn the ignition switch to LOCK (0).
13. Start the engine, and watch the TPMS indicator.
Does the TPMS indicator come on and go off?
YES -
Go to step 18.
NO -
Go to the TPMS symptom troubleshooting for TPMS indicator does not go off, and no DTCs are stored TPMS Symptom Troubleshooting - Low Tire Pressure/TPMS Indicator Does Not Go Off, And No DTCs Are Stored.
14. Turn the ignition switch to LOCK (0).
15. Turn the ignition switch to ON (II), and watch the immobilizer indicator.
Does the immobilizer indicator stay on or flash?
YES -
Go to the immobilizer system's troubleshooting Immobilizer System Symptom Troubleshooting Information.
NO -
Go to step 18.
16. Do the gauge self-diagnostic function Testing and Inspection.
17. Check the gauge display.
Is Error 2 indicated?
YES -
Check for B-CAN system DTCs.
NO -
Go to step 18.
18. Turn the ignition switch to LOCK (0), then do the 12 volt battery terminal disconnection procedure Procedures, and wait at least 3 minutes before continuing.
19. Disconnect the HDS from the DLC.
20. Check for continuity between DLC terminal No. 7 and body ground.
Is there continuity?
YES -
Go to step 21.
NO -
Go to step 22.
21. Continue to check for continuity between DLC terminal No. 7 and body ground, while disconnecting these connectors, one at a time:
- SRS unit connector A (39P)
- VSA modulator-control unit 32P connector
- EPS control unit connector A (11P)
- TPMS control unit 20P connector
- Immobilizer-keyless control unit 7P connector
- Audio-navigation unit connector A (24P) (with navigation)
- Audio unit connector A (24P) (without navigation)
- Under-dash fuse/relay box connector Y (16P)
Does continuity go away when one of the above connectors is disconnected?
YES -
Replace the part that caused continuity go away when it was disconnected.
NO -
Repair a short in the wire between the DLC (K-line) and the VSA modulator-control unit, the SRS unit, the EPS control unit, the TPMS control unit, the immobilizer-keyless control unit, the audio-navigation unit (with navigation), the audio unit (without navigation), or the under-dash fuse/relay box.
22. Connect DLC terminal No. 7 to body ground with a jumper wire.
23. Check for continuity between body ground and these connector terminals:
Is there continuity between body ground and each of the terminals in the chart?
YES -
Replace the part that does not communicate with the HDS.
NO -
Repair an open in the wire between the DLC (K-line) and the appropriate connector.
24. Check for B-CAN system DTCs without the HDS Reading and Clearing Diagnostic Trouble Codes.
Is DTC U0029 and/or U0100 indicated?
YES -
Go to the F-CAN circuit troubleshooting F-CAN Circuit Troubleshooting.
NO -
Go to step 25.
25. Turn the ignition switch to LOCK (0).
26. Disconnect the HDS from the DLC.
27. Measure the voltage between DLC terminal No. 16 and body ground.
Is there battery voltage?
YES -
Go to step 28.
NO -
Repair an open in the wire between DLC terminal No. 16 and the No. B1 BACK UP (15 A) fuse in the under-dash fuse/relay box.
28. Measure the voltage between DLC terminals No. 4 and No. 16.
Is there battery voltage?
YES -
Go to step 29.
NO -
Repair an open in the wire between DLC terminal No. 4 and body ground (G502).
29. Connect the HDS to the DLC.
30. Jump the SCS line with the HDS.
31. Disconnect ECM/PCM connector A (44P).
32. Disconnect the HDS from the DLC.
33. Check for continuity between ECM/PCM connector terminal A36 and DLC terminal No. 6.
Is there continuity?
YES -
Go to step 34.
NO -
Repair an open in the wire between the ECM/PCM (A36) and DLC terminal No. 6.
34. Check for continuity between ECM/PCM connector terminal A37 and DLC terminal No. 14.
Is there continuity?
YES -
Update the ECM/PCM if it does not have the latest software ECM/PCM Update, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away and the ECM/PCM was updated, troubleshooting is complete. If the symptom/indication goes away and the ECM/PCM was substituted, replace the original ECM/PCM Service and Repair.
NO -
Repair an open in the wire between the ECM/PCM (A37) and DLC terminal No. 14.