DLC Circuit Troubleshooting
- Turn the ignition switch to LOCK (0).
- Connect the HDS to the DLC (see GENERAL TROUBLESHOOTING INFORMATION
).NOTE: Make sure the HDS is properly connected to the DLC.
- 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 25.
- 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 5.
- If the HDS does not communicate with the VSA system, go to step 7.
- If the HDS does not communicate with the ABS, go to step 9.
- If the HDS does not communicate with the EPS system, go to step 11.
- If the HDS does not communicate with the TPMS, go to step 13.
- If the HDS does not communicate with the IMMOBI (immobilizer) system, go to step 15.
- If the HDS does not communicate with the BODY ELECTRICAL system, go to step 17.
- Turn the ignition switch to LOCK (0).
- 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 SRS indicator stays on, but no DTC are stored (see SYMPTOM TROUBLESHOOTING ).
- Turn the ignition switch to LOCK (0).
- 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 system symptom troubleshooting for ABS indicator, brake system indicator, and VSA indicator do not go off (see ABS INDICATOR, BRAKE SYSTEM INDICATOR, AND VSA INDICATOR DO NOT GO OFF ).
- Turn the ignition switch to LOCK (0).
- Turn the ignition switch to ON (II), and watch the ABS indicator.
Does the ABS indicator come on and go off?
YES: Go to step 17.
NO: Go to the ABS symptom troubleshooting for ABS indicator and brake system indicator do not go off (see DTC 86-FF: F-CAN COMMUNICATION WITH ABS MALFUNCTION ).
- Turn the ignition switch to LOCK (0).
- 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 system symptom troubleshooting for EPS indicator does not go off, and no DTCs are stored (see SYMPTOM TROUBLESHOOTING ).
- Turn the ignition switch to LOCK (0).
- Turn the ignition switch to ON (II), and watch the TPMS indicator.
Does the TPMS indicator stay on?
YES: Go to the TPMS GENERAL TROUBLESHOOTING INFORMATION .
NO: Go to step 17.
- Turn the ignition switch to LOCK (0).
- 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 troubleshooting (see SYSTEM DESCRIPTION ).
NO: Go to step 17.
- Do the gauge self-diagnostic function (see SELF-DIAGNOSTIC FUNCTION ).
- Check the gauge display.
Is Error 2 indicated?
YES: Check for B-CAN system DTCs (see GENERAL TROUBLESHOOTING INFORMATION ).
NO: Go to step 19.
- Turn the ignition switch to LOCK (0), then do the battery terminal disconnection procedure (see BATTERY TERMINAL DISCONNECTION AND RECONNECTION ), and wait at least 3 minutes before starting work.
- Disconnect the HDS from the DLC.
- Check for continuity between DLC terminal No. 7 and body ground.
Is there continuity?
YES: Go to step 22.
NO: Go to step 23.
- 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)
- ABS modulator-control unit 25P connector (with ABS)
- VSA modulator-control unit 36P connector (with VSA system)
- EPS control unit connector A (11P)
- TPMS control unit 20P connector
- Immobilizer-keyless control unit 7P connector
- Audio unit 24P connector
- Under-dash fuse/relay box Q (16P) connector
Does continuity go away when one of the above parts is disconnected?
YES: Replace the part that caused continuity to go away when it was disconnected.
NO: Repair short in the wire between the DLC (K-line) and the ABS modulator-control unit (with ABS), the VSA modulator-control unit (with VSA system), the SRS unit, the EPS control unit, the TPMS control unit, the immobilizer-keyless control unit, the audio unit, the under-dash fuse/relay box, or the ECM/PCM.
- Connect DLC terminal No. 7 to body ground with a jumper wire.
- Check for continuity between body ground and these connector terminals:CONNECTOR TERMINAL REFERENCE TABLE
Connector Terminal SRS unit A (39P) No. 18 (BLU) VSA modulator-control unit 36P (with VSA system) No. 3 (BLU) ABS control unit 25P (with ABS) No. 10 (BLU) EPS control unit A (11P) No. 7 (BLU) TPMS control unit 20P No. 7 (BLU) Immobilizer-keyless control unit 7P No. 5 (BLU) Audio unit 24P No. 3 (BLU) Under-dash fuse/relay box Q (16P) No. 2 (BLU) Is there continuity between the DLC terminal and each of the terminals in the table?
YES: Replace the part that does not communicate with the HDS.
NO: Repair open in the wire between the DLC (K-line) and the appropriate connector.
- Do the gauge self-diagnostic function (see SELF-DIAGNOSTIC FUNCTION
).
Is Error 1 indicated?
YES: Go to step 36.
NO: Go to step 26.
- Turn the ignition switch to LOCK (0).
- Disconnect the HDS from the DLC.
- Measure the voltage between DLC terminal No. 16 and body ground.
Is there battery voltage?
YES: Go to step 29.
NO: Repair open in the wire between DLC terminal No. 16 and the No. 1 BACK UP (10 A) fuse in the under-dash fuse/relay box.
- Measure the voltage between DLC terminals No. 4 and No. 16.
Is there battery voltage?
YES: Go to step 30.
NO: Repair open in the wire between DLC terminal No. 4 and body ground (G502) (see CONNECTOR TO FUSE/RELAY BOX INDEX ).
- Connect the HDS to the DLC (see GENERAL TROUBLESHOOTING INFORMATION ).
- Jump the SCS line with the HDS.
- Disconnect ECM/PCM connector A (49P).
- Disconnect the HDS from the DLC.
- Check for continuity between ECM/PCM connector terminal A3 and DLC terminal No. 6.
Is there continuity?
YES: Go to step 35.
NO: Repair open in the wire between the ECM/PCM (A3) and DLC terminal No. 6.
- Check for continuity between ECM/PCM connector terminal A4 and DLC terminal No. 14.
Is there continuity?
YES: Update the ECM/PCM if it does not have the latest software (see ECM/PCM UPDATE ), or substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see ECM/PCM REPLACEMENT ).
NO: Repair open in the wire between the ECM/PCM (A4) and DLC terminal No. 14.
- Try to start the engine.
Does the engine start and idle smoothly?
YES: Go to F-CAN CIRCUIT TROUBLESHOOTING .
NO: Go to step 37.
- Turn the ignition switch to LOCK (0).
- Check the No. 60 IG MAIN (50 A) fuse in the under-dash fuse/relay box.
Is the fuse OK?
YES: Repair open in the wire the No. 60 IG MAIN (50 A) fuse and the ignition switch. If the wire is OK go to step 39.
NO: Repair short in the wire between the No. 60 IG MAIN (50 A) fuse and the under-dash fuse/relay box. Also replace the No. 60 IG MAIN (50 A) fuse.
- Inspect the No. 39 IGP (15 A) fuse in the under-dash fuse/relay box.
Is the fuse OK?
YES: Go to step 46.
NO: Go to step 40.
- Remove the blown No. 39 IGP (15 A) fuse from the under-hood fuse/relay box.
- Open the fuse access panel (A), then remove the PGM-FI main relay 1 (B) from the under-dash fuse/ relay box.
- Check for continuity between body ground and PGM-FI main relay 1 4P connector terminals No. 2 and No. 3 individually.Fig 8: Checking Continuity Between Body Ground And PGM-FI Main Relay 1 4P Connector Terminals No. 2 & No. 3
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES: Replace the under-dash fuse/relay box (see REMOVAL AND INSTALLATION ).
NO: Go to step 43.
- 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
- ECM/PCM connector A (49P)
- Each injector 2P connector
- Camshaft position (CMP) sensor 3P connector
- Crankshaft position (CKP) sensor 3P connector
- Electronic throttle control system (ETCS) control relay
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Does continuity go away when one of the above parts is disconnected?
YES: Replace the part that made the short to body ground go away when disconnected. If the part is the ECM/PCM, update the ECM/PCM if it does not have the latest software (see ECM/PCM UPDATE ), or substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see ECM/PCM REPLACEMENT ). Also replace the No. 39 IGP (15A) fuse.
NO: Go to step 44.
- Disconnect these parts or connectors:
- PGM-FI main relay 2
- ECM/PCM connector A
- Injectors
- Camshaft position (CMP) sensor
- Crankshaft position (CKP) sensor
- Electronic throttle control system (ETCS) control relay
- Check for continuity between PGM-FI main relay 1 4P connector terminal No. 1 and body ground.
Is the fuse OK?
YES: Repair 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.
- Inspect the No. 20 FUEL PUMP (15 A) fuse in the under-dash fuse/relay box.
Is the fuse OK?
YES: Go to step 56.
NO: Go to step 47.
- Remove the blown No. 20 FUEL PUMP (15 A) fuse from the under-dash fuse/relay box.
- Open the fuse access panel (A), then remove PGM-FI main relay 2 (B) from the under-dash fuse/relay box.
- Test PGM-FI main relay 2 (see POWER RELAY TEST
).
Is the relay OK?
YES - Go to step 50.
NO - Replace PGM-FI main relay 2. Also replace the No. 20 FUEL PUMP (15 A) fuse.
- Check for continuity between PGM-FI main relay 2 4P connector terminal No. 2 and body ground.
Is the continuity?
YES - Go to step 51.
NO - Go to step 54.
- Jump the SCS line with the HDS.
- Disconnect ECM/PCM connector C (49P).
- Check for continuity between ECM/PCM connector terminal C10 and body ground.
Is there continuity?
YES: Repair short in the wire between the No. 20 FUEL PUMP (15 A) fuse and the ECM/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 ECM/PCM if it does not have the latest software (see ECM/PCM UPDATE ), or substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see ECM/PCM REPLACEMENT ).
- Disconnect the fuel pump 4P connector (see FUEL TANK UNIT REMOVAL AND INSTALLATION ).
- Check for continuity between fuel pump 4P connector terminal No. 2 and body ground.
Is there continuity?
YES: Repair 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 (see FUEL PRESSURE REGULATOR REPLACEMENT ). Also replace the No. 20 FUEL PUMP (15 A) fuse.
- Jump the SCS line with the HDS.
- Disconnect ECM/PCM connectors A (49P) and C (49P).
- Turn the ignition switch to ON (II).
- Measure the voltage between ECM/PCM connector terminal C10 and body ground.
Is there battery voltage?
YES: Go to step 60.
NO: Repair open in the wire between the No. 20 FUEL PUMP (15 A) fuse and the ECM/PCM (C10).
- Measure the voltage between ECM/PCM connector terminal A7 and body ground.
Is there battery voltage?
YES: Go to step 66.
NO: Go to step 61.
- Turn the ignition switch to LOCK (0).
- Open the fuse access panel (A), then remove the PGM-FI main relay 1 (B) from the under-dash fuse/ relay box.
- 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 64.
NO: Replace the under-dash fuse/relay box (see REMOVAL AND INSTALLATION ).
- Connect PGM-FI main relay 1 4P connector terminal No. 4 to body ground with a jumper wire.
- Check for continuity between ECM/PCM connector terminal A7 and body ground.
Is there continuity?
YES: Test PGM-FI main relay 1 (see POWER RELAY TEST ). If the relay is OK, update the ECM/PCM if it does not have the latest software (see ECM/PCM UPDATE ), or substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see ECM/PCM REPLACEMENT ).
NO: Repair open in the wire between the ECM/PCM (A7) and PGM-FI main relay 1.
- Turn the ignition switch to LOCK (0).
- Open the fuse access panel (A), then remove the PGM-FI main relay 1 (B) from the under-dash fuse/ relay box.
- 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 69.
NO: Replace the under-dash fuse/relay box (see REMOVAL AND INSTALLATION ).
- Connect PGM-FI main relay 1 4P connector terminal No. 1 to body ground with a jumper wire.
- Check for continuity between ECM/PCM connector terminal A9 and body ground.
Is there continuity?
YES: Go to step 71.
NO: Repair open in the wire between the ECM/PCM (A9) and PGM-FI main relay 1.
- Test PGM-FI main relay 1 (see POWER RELAY TEST
).
Is PGM-FI main relay 1 OK?
YES: Go to step 72.
NO: Replace PGM-FI main relay 1.
- Disconnect ECM/PCM connector B (49P).
- Check for continuity between body ground and ECM/PCM connector terminals B1, B10, C2, C44 and C48 individually.
Is there continuity?
YES: Go to step 74.
NO: Repair open in the wire between the ECM/PCM (B1, B10, C2, C44, C48) and G101.
- Check for continuity between ECM/PCM connector terminal C13 and body ground.
Is there continuity?
YES: Go to step 75.
NO: Go to step 76.
- Continue to check for continuity between ECM/PCM connector terminal C13 and body ground, while disconnecting these connectors, one at a time:
- MAP sensor 3P connector
- Output shaft (countershaft) speed sensor 3P connector
Does continuity go away when one of the above parts is disconnected?
YES: Replace the part that caused continuity to go away when it was disconnected.
NO: Repair short in the wire between the ECM/PCM (C13) and the MAP sensor or the output shaft (countershaft) speed sensor.
- Check for continuity between ECM/PCM connector terminal B19 and body ground.
Is there continuity?
YES: Go to step 77.
NO: Go to step 78.
- Continue to check for continuity between ECM/PCM connector terminal B19 and body ground, while disconnecting these connectors, one at a time:
- EGR valve 6P connector
- Input shaft (mainshaft) speed sensor 3P connector
Does continuity go away when one of the above parts is disconnected?
YES: Replace the part that caused continuity to go away when it was disconnected.
NO: Repair short in the wire between the ECM/PCM (B19) and the EGR valve or the input shaft (mainshaft) speed sensor.
- Check for continuity between ECM/PCM connector terminal C12 and body ground.
Is there continuity?
YES: Go to step 79.
NO: Go to step 80.
- Continue to check for continuity between ECM/PCM connector terminal C12 and body ground, while disconnecting the throttle body 6P connector.
Is there continuity?
YES: Repair short in the wire between the ECM/PCM (C12) and the throttle body.
NO: Replace the throttle body (see THROTTLE BODY REMOVAL/INSTALLATION ).
- Check for continuity between ECM/PCM connector terminal A26 and body ground.
Is there continuity?
YES: Go to step 81.
NO: Go to step 82.
- Continue to check for continuity between ECM/PCM connector terminal A26 and body ground, while disconnecting the APP sensor 6P connector.
Is there continuity?
YES: Repair short in the wire between the ECM/PCM (A26) and APP sensor A.
NO: Replace the accelerator pedal module (see ACCELERATOR PEDAL MODULE REMOVAL/INSTALLATION ).
- Check for continuity between ECM/PCM connector terminal A25 and body ground.
Is there continuity?
YES: Go to step 83.
NO: Go to step 84.
- Continue to check for continuity between ECM/PCM connector terminal A25 and body ground, while disconnecting the APP sensor 6P connector.
Is there continuity?
YES: Repair short in the wire between the ECM/PCM (A25) and APP sensor B.
NO: Replace the accelerator pedal module (see ACCELERATOR PEDAL MODULE REMOVAL/INSTALLATION ).
- Check for continuity between ECM/PCM connector terminal A20 and body ground.
Is there continuity?
YES: Go to step 85.
NO: Update the ECM/PCM if it does not have the latest software (see ECM/PCM UPDATE ), or substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see ECM/PCM REPLACEMENT ).
- Continue to check for continuity between ECM/PCM connector terminal A20 and body ground, while disconnecting the FTP sensor 3P connector.
Is there continuity?
YES: Repair short in the wire between the ECM/PCM (A20) and the FTP sensor.
NO: Replace the FTP sensor (see FTP SENSOR REPLACEMENT ).