DLC Circuit Troubleshooting (PGM-FI System)
DLC Circuit Troubleshooting
NOTE: If you suspect the HDS or 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 problem.
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 4.
NO -
Go to step 23.
4. 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 system, go to step 5.
- If the HDS does not communicate with the VSA system, go to step 7.
- If the HDS does not communicate with the EPS system, go to step 9.
- If the HDS does not communicate with the TPMS system, go to step 11.
- If the HDS does not communicate with the IMMOBI (immobilizer) system, go to step 13.
- If the HDS does not communicate with the BODY ELECTRICAL system, go to step 15.
5. Turn the ignition switch to LOCK (0).
6. 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 17.
NO -
Go to the SRS symptom troubleshooting for an SRS indicator that stays on with no stored DTCs SRS Indicator Stays On, But No DTCs Are Stored, Or Cannot Be Read.
7. Turn the ignition switch to LOCK (0).
8. 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 17.
NO -
Go to the VSA symptom troubleshooting for an ABS indicator, brake system indicator, and VSA indicator that do not go off Symptom Troubleshooting.
9. Turn the ignition switch to LOCK (0).
10. Start the engine, and watch the EPS indicator.
Does the EPS indicator come on and go off?
YES -
Go to step 17.
NO -
Go to the EPS symptom troubleshooting for an EPS indicator that does not go off with no stored DTCs EPS Indicator Does Not Go Off, And No DTCs.
11. Turn the ignition switch to LOCK (0).
12. Turn the ignition switch to ON (II), and watch the TPMS indicator.
Does the TPMS indicator come on and go off?
YES -
Go to step 17.
NO -
Go to the TPMS symptom troubleshooting for TPMS indicator does not go off, and no DTC stored TPMS Symptom Troubleshooting - Low Tire Pressure/TPMS Indicator Does Not Go Off, And No DTCs Are Stored.
13. Turn the ignition switch to LOCK (0).
14. 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 17.
15. Do the gauge self-diagnostic function Testing and Inspection.
16. Check the gauge display.
Is Error 2 indicated?
YES -
Check for B-CAN system DTCs.
NO -
Go to step 17.
17. 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.
18. Disconnect the HDS from the DLC.
19. Check for continuity between DLC terminal No. 7 and body ground.
Is there continuity?
YES -
Go to step 20.
NO -
Go to step 21.
20. Continue to check for continuity between DLC terminal No. 7 and body ground, while disconnecting these parts, one at a time:
- SRS unit connector A (39P)
- VSA modulator-control unit 47P connector
- EPS control unit connector C (16P)
- TPMS control unit 20P connector
- Immobilizer-keyless control unit 7P connector
- Audio-navigation unit connector A (24P)
- Audio unit connector A (24P)
- Under-dash fuse/relay box connector Q (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 immobilizer-keyless control unit, the audio-navigation unit, the audio unit, or the under-dash fuse/relay box.
21. Connect DLC terminal No. 7 to body ground with a jumper wire.
22. 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.
23. Check for B-CAN system DTCs without the HDS.
Is DTC U0029 and/or U0100 indicated?
YES -
Go to step 34.
NO -
Go to step 24.
24. Turn the ignition switch to LOCK (0).
25. Disconnect the HDS from the DLC.
26. Measure the voltage between DLC terminal No. 16 and body ground.
Is there battery voltage?
YES -
Go to step 27.
NO -
Repair an open in the wire between DLC terminal No. 16 and the No. 1 BACK UP (15A) fuse in the under-dash fuse/relay box.
27. Measure the voltage between DLC terminals No. 4 and No. 16.
Is there battery voltage?
YES -
Go to step 28.
NO -
Repair an open in the wire between DLC terminal No. 4 and body ground (G502).
28. Connect the HDS to the DLC.
29. Jump the SCS line with the HDS.
30. Disconnect PCM connector A (49P).
31. Disconnect the HDS from the DLC.
32. Check for continuity between PCM connector terminal A3 and DLC terminal No. 6.
Is there continuity?
YES -
Go to step 33.
NO -
Repair an open in the wire between the PCM (A3) and DLC terminal No. 6.
33. Check for continuity between PCM connector terminal A4 and DLC terminal No. 14.
Is there continuity?
YES -
Update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If the symptom/indication goes away and the PCM was updated, troubleshooting is complete. If the symptom/indication goes away and the PCM was substituted, replace the original PCM.
NO -
Repair an open in the wire between the PCM (A4) and DLC terminal No. 14.
34. Try to start the engine.
Does the engine start and idle smoothly?
YES -
Go to F-CAN circuit troubleshooting F-CAN Circuit Troubleshooting.
NO -
Go to step 35.
35. Turn the ignition switch to LOCK (0).
36. Check the No. 60 IG SW (50 A) fuse in the under-dash fuse/relay box.
Is the fuse OK?
YES -
Repair an open in the wire between the No. 60 IG SW (50 A) fuse and the ignition switch. If the wire is OK go to step 37.
NO -
Repair a short in the wire between the No. 60 IG SW (50 A) fuse and the under-dash fuse/relay box. Also replace the No. 60 IG SW (50 A) fuse.
37. Inspect the No. 39 IGP (15 A) fuse in the under-dash fuse/relay box.
Is the fuse OK?
YES -
Go to step 44.
NO -
Go to step 38.
38. Remove the blown No. 39 IGP (15 A) fuse from the under-dash fuse/relay box.
39. Open the fuse access panel (A), then remove PGM-FI main relay 1 (B) from the under-dash fuse/relay box.
40. Check for continuity between body ground and PGM-FI main relay 1 4P connector terminals No. 2 and No. 3 individually.
Is there continuity?
YES -
Replace the under-dash fuse/relay box (USA model) Under-Dash Fuse/Relay Box Removal and Installation (USA Models), (Canada model) Under-Dash Fuse/Relay Box Removal and Installation (Canada Models).
NO -
Go to step 41.
41. While disconnecting each of the parts or connectors below, one at a time, check for continuity between PGM-FI main relay 1 4P connector terminal No. 1 and body ground.
- PGM-FI main relay 2
- PCM connector A (49P)
- Each injector 2P connector
- CMP sensor 3P connector
- CKP sensor 3P connector
- Electronic throttle control system (ETCS) control relay
Does continuity go away when one of the above parts or components is disconnected?
YES -
Replace the part that made the short to body ground go away when disconnected. If the part is the PCM, update the PCM if it does not have the latest software PCM Update, or substitute a known-good PCM, then recheck. If the symptom/indication goes away and the PCM was updated, troubleshooting is complete. If the symptom/indication goes away and the PCM was substituted, replace the original PCM Service and Repair. Also replace the No. 39 IGP (15 A) fuse.
NO -
Go to step 42.
42. Disconnect the connectors from these parts:
- PGM-FI main relay 2
- PCM connector A (49P)
- Each injector 2P connector
- CMP sensor 3P connector
- CKP sensor 3P connector
- Electronic throttle control (ETCS) control relay
43. Check for continuity between PGM-FI main relay 1 4P connector terminal No. 1 and body ground.
Is there continuity?
YES -
Repair a short in the wire between PGM-FI main relay 1 and each part. Also replace the No. 39 IGP (15 A) fuse.
NO -
Replace PGM-FI main relay 1. Also replace the No. 39 IGP (15 A) fuse.
44. Inspect the No. 20 FUEL PUMP (15 A) fuse in the under-dash fuse/relay box.
Is the fuse OK?
YES -
Go to step 54.
NO -
Go to step 45.
45. Remove the blown No. 20 FUEL PUMP (15 A) fuse from the under-dash fuse/relay box.
46. Remove PGM-FI main relay 2 (A) from the auxiliary under-hood fuse/relay box.
47. Test PGM-FI main relay 2.
Is the relay OK?
YES -
Go to step 48.
NO -
Replace PGM-FI main relay 2. Also replace the No. 20 FUEL PUMP (15 A) fuse.
48. Check for continuity between PGM-FI main relay 2 4P connector terminal No. 1 and body ground.
Is there continuity?
YES -
Go to step 49.
NO -
Go to step 52.
49. Jump the SCS line with the HDS.
50. Disconnect PCM connector C (49P).
51. Check for continuity between PCM connector terminal C10 and body ground.
Is there continuity?
YES -
Repair a short in the wire between the No. 20 FUEL PUMP (15 A) fuse and the PCM (C10) or PGM-FI main relay 2. Also replace the No. 20 FUEL PUMP (15 A) fuse.
NO -
Replace the No. 20 FUEL PUMP (15 A) fuse, and update the PCM if it does not have the latest software PCM Update, or substitute a known-good PCM, then recheck. If the symptom/indication goes away and the PCM was updated, troubleshooting is complete. If the symptom/indication goes away and the PCM was substituted, replace the original PCM Service and Repair.
52. Disconnect the fuel pump 4P connector Fuel Tank Unit Removal/Installation.
53. Check for continuity between fuel pump 4P connector terminal No. 2 and body ground.
Is there continuity?
YES -
Repair a short in the wire between the fuel pump and PGM-FI main relay 2. Also replace the No. 20 FUEL PUMP (15 A) fuse.
NO -
Check the fuel pump, and replace it if needed Fuel Pump/Fuel Gauge Sending Unit Replacement. Also replace the No. 20FUEL PUMP (15 A) fuse.
54. Jump the SCS line with the HDS.
55. Disconnect PCM connectors A (49P) and C (49P).
56. Turn the ignition switch to ON (II).
57. Measure the voltage between PCM connector terminal C10 and body ground.
Is there battery voltage?
YES -
Go to step 58.
NO -
Repair an open in the wire between the No. 20 FUEL PUMP (15 A) fuse and the PCM (C10).
58. Measure the voltage between PCM connector terminal A7 and body ground.
Is there battery voltage?
YES -
Go to step 64.
NO -
Go to step 59.
59. Turn the ignition switch to LOCK (0).
60. Open the fuse access panel (A), then remove PGM-FI main relay 1 (B) from the under-dash fuse/relay box.
61. Measure the voltage between PGM-FI main relay 1 4P connector terminal No. 3 and body ground.
Is there battery voltage?
YES -
Go to step 62.
NO -
Replace the under-dash fuse/relay box (USA model) Under-Dash Fuse/Relay Box Removal and Installation (USA Models), (Canada model) Under-Dash Fuse/Relay Box Removal and Installation (Canada Models).
62. Connect PGM-FI main relay 1 4P connector terminal No. 4 to body ground with a jumper wire.
63. Check for continuity between PCM connector terminal A7 and body ground.
Is there continuity?
YES -
Test PGM-FI main relay 1 Testing and Inspection. If the relay is OK, update the PCM if it does not have the latest software PCM Update, or substitute a known-good PCM, then recheck. If the symptom/indication goes away and the PCM was updated, troubleshooting is complete. If the symptom/indication goes away and the PCM was substituted, replace the original PCM Service and Repair.
NO -
Repair an open in the wire between the PCM (A7) and PGM-FI main relay 1.
64. Turn the ignition switch to LOCK (0).
65. Open the fuse access panel (A), then remove PGM-FI main relay 1 (B) from the under-dash fuse/relay box.
66. Measure the voltage between PGM-FI main relay 1 4P connector terminal No. 2 and body ground.
Is there battery voltage?
YES -
Go to step 67.
NO -
Replace the under-dash fuse/relay box (USA model) Under-Dash Fuse/Relay Box Removal and Installation (USA Models), (Canada model) Under-Dash Fuse/Relay Box Removal and Installation (Canada Models).
67. Connect PGM-FI main relay 1 4P connector terminal No. 1 to body ground with a jumper wire.
68. Check for continuity between body ground and PCM connector terminals A9 individually.
Is there continuity?
YES -
Remove the jumper wire, then go to step 69.
NO -
Repair an open in the wire between the PCM (A9) and PGM-FI main relay 1.
69. Disconnect PCM connector B (49P).
70. Check for continuity between body ground and PCM connector terminals B1, B10, C2, C44, and C49 individually.
Is there continuity?
YES -
Go to step 72.
NO -
Repair an open in the wire between the PCM (B1, B10, C2, C44, C49) and G101.
71. Check for continuity between PCM connector terminal C13 and body ground.
Is there continuity?
YES -
Go to step 72.
NO -
Go to step 73.
72. Continue to check for continuity between PCM connector terminal C13 and body ground, while disconnecting these connectors, one at a time:
- MAP sensor 3P connector
- CVT output shaft (driven pulley) speed sensor 3P connector
Does continuity go away when one of the above connectors is disconnected?
YES -
Replace the part that made the short to body ground go away when disconnected.
NO -
Repair a short in the wire between the PCM (C13) and the MAP sensor or the CVT output shaft (driven pulley) speed sensor.
73. Check for continuity between PCM connector terminal B19 and body ground.
Is there continuity?
YES -
Go to step 74.
NO -
Go to step 75.
74. Continue to check for continuity between PCM connector terminal B19 and body ground, while disconnecting these connectors, one at a time:
- Rocker arm oil pressure sensor A and B 3P connectors
- EGR valve 5P connector
- CVT input shaft (drive pulley) speed sensor 3P connector
- Vehicle speed sensor 3P connector
- CVT driven pulley pressure sensor 3P connector
Does continuity go away when one of the above connectors is disconnected?
YES -
Replace the part that made the short to body ground go away when disconnected.
NO -
Repair a short in the wire between the PCM (B16) and rocker arm oil pressure sensor A and B, the EGR valve, the CVT input shaft (drive pulley) speed sensor, the vehicle speed sensor or the CVT driven pulley pressure sensor.
75. Check for continuity between PCM connector terminal C12 and body ground.
Is there continuity?
YES -
Go to step 76.
NO -
Go to step 77.
76. Continue to check for continuity between PCM connector terminal C12 and body ground, while disconnecting the throttle body 6P connector.
Is there continuity?
YES -
Repair a short in the wire between the PCM (C12) and the throttle body.
NO -
Replace the throttle body Removal and Replacement.
77. Check for continuity between PCM connector terminal A26 and body ground.
Is there continuity?
YES -
Go to step 78.
NO -
Go to step 79.
78. Continue to check for continuity between PCM connector terminal A26 and body ground, while disconnecting the APP sensor 6P connector.
Is there continuity?
YES -
Repair a short in the wire between the PCM (A26) and APP sensor A.
NO -
Replace the accelerator pedal module Service and Repair.
79. Check for continuity between PCM connector terminal A25 and body ground.
Is there continuity?
YES -
Go to step 80.
NO -
Go to step 81.
80. Continue to check for continuity between PCM connector terminal A25 and body ground, while disconnecting the APP sensor 6P connector.
Is there continuity?
YES -
Repair a short in the wire between the PCM (A25) and APP sensor B.
NO -
Replace the accelerator pedal module Service and Repair.
81. Check for continuity between PCM connector terminal A20 and body ground.
Is there continuity?
YES -
Go to step 82.
NO -
Update the PCM if it does not have the latest software PCM Update, or substitute a known-good PCM, then recheck. If the symptom/indication goes away and the PCM was updated, troubleshooting is complete. If the symptom/indication goes away and the PCM was substituted, replace the original PCM Service and Repair.
82. Continue to check for continuity between PCM connector terminal A20 and body ground, while disconnecting these connectors, one at a time:
- A/C pressure sensor 3P connectors
- Brake booster pressure sensor A 3P connector
- Brake booster pressure sensor B 3P connector
- FTP sensor 3P connector
Does continuity go away when one of the above connectors is disconnected?
YES -
Repair the part that made the short to body ground go away when disconnected.
NO -
Repair a short in the wire between the PCM (A20) and brake booster pressure sensor A, brake booster pressure sensor B, the A/C pressure sensor, or the FTP sensor.