Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
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 or DTCs in the PGM-FI system with the HDS.
Are any Pending or Confirmed or DTCs indicated?
YES -Go to the INDICATED DTC'S TROUBLESHOOTING .
NO -Go to step 5.
- 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 -
- With VSA: Go to step 7.
- With VSA : Go to step 9.
NO -Go to the SRS general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).
- 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 11.
NO -Go to the ABS symptom troubleshooting for ABS indicator and brake system indicator do not go off (see ABS INDICATOR AND BRAKE SYSTEM INDICATOR DO NOT GO OFF ).
- Turn the ignition switch to LOCK (0).
- Turn the ignition switch to ON (II), and watch the VSA indicator.
Does the VSA indicator stay on?
YES -Go to the VSA system's general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).
NO -Go to step 11.
- Turn the ignition switch to LOCK (0).
- Start the engine, and watch the EPS indicator.
Does the EPS indicator stay on?
YES -Go to step 13.
NO -Go to the EPS system's general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).
- 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's troubleshooting (see SYMPTOM TROUBLESHOOTING INFORMATION ).
NO -
- With TPMS: Go to step 15.
- Without TPMS: Go to step 17.
- 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 indicator system's troubleshooting (see SYSTEM INDICATOR ).
NO -Go to step 17.
- Do the gauge self-diagnostic function (see SELF-DIAGNOSTIC FUNCTION ).
- Check for B-CAN system DTCs without the HDS (see GENERAL TROUBLESHOOTING INFORMATION
).
Are any B-CAN DTCs indicated?
YES -Go to the INDICATED DTC'S TROUBLESHOOTING .
NO -Go to step 19.
- Turn the ignition switch to LOCK (0), then do the battery terminal disconnection procedure, and wait at least 3 minutes before continuing.
- Disconnect the HDS from the DLC.
- Check for continuity between DLC terminal No. 7 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
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 (28P)
- ABS modulator-control unit 25P connector (with ABS)
- VSA modulator-control unit 37P connector (with VSA system)
- EPS control unit connector D (28P)
- Immobilizer-keyless control unit 7P connector
- TPMS control unit 20P connector (with TPMS)
- Audio unit 17P connector
- Under-dash fuse/relay box Q (16P) connector
Does continuity go away when one of the above components is disconnected?
YES -Replace the part that caused an open 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 immobilizer-keyless control unit, the TPMS control unit (with TPMS), the audio unit, or the under-dash fuse/relay box.
- Connect DLC terminal No. 7 to body ground with a jumper wire.
- Check for continuity between body ground and these connector terminals:CONNECTOR TERMINAL CHART
Connector Terminal SRS unit A(28P) No. 24 (LT BLU) ABS modulator-control unit 25P (with ABS) No. 10 (LT BLU) VSA modulator-control unit 37P (with VSA system) No. 26 (LT BLU) EPS control unit D (28P) No. 17 (LT BLU) Immobilizer-keyless control unit 7P No. 5 (LT BLU) TPMS control unit 20P No. 7 (LT BLU) Audio unit 17P No. 6 (LT BLU) Under-dash fuse/relay box Q (16P) No. 8 (LT BLU) Is there continuity between the body ground and each of the terminals in the chart?
YES -Replace the unit 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 ).
- Check for B-CAN system DTCs without the HDS (see GENERAL TROUBLESHOOTING INFORMATION
).
Is DTC B1168, B1169, and/or B1178 indicated?
YES -Go to step 37.
NO -Go to step 27.
- Turn the ignition switch to LOCK (0).
- Disconnect the HDS from the DLC.
- Measure the voltage between DLC terminal No. 16 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES -Go to step 30.
NO -Repair open in the wire between DLC terminal No. 16 and the No. 23 BACK UP (10 A) fuse in the under-hood fuse/relay box.
- Measure the voltage between DLC terminals No. 4 and No. 16.
Is there battery voltage?
YES -Go to step 31.
NO -Repair open in the wire between DLC terminal No. 4 and body ground (G502) (see DASHBOARD WIRE HARNESS (VIEW OF PASSENGER'S SIDE) ).
- Connect the HDS to the DLC (see GENERAL TROUBLESHOOTING INFORMATION ).
- Jump the SCS line with the HDS.
- Disconnect ECM connector A (44P).
- Disconnect the HDS from the DLC.
- Check for continuity between ECM connector terminal A36 and DLC terminal No. 6.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Go to step 36.
NO -Repair open in the wire between DLC terminal No. 6 and the ECM (A36).
- Check for continuity between ECM connector terminal A37 and DLC terminal No. 14.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Reconnect all connectors, then update the ECM if it does not have the latest software (see ECM UPDATE ), or substitute a known- good ECM (see SUBSTITUTING THE ECM ), then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM (see ECM REPLACEMENT ).
NO -Repair open in the wire between DLC terminal No. 14 and the ECM (A37)
- Try to start the engine.
Does the engine start and idle smoothly?
YES -Go to the F-CAN CIRCUIT TROUBLESHOOTING .
NO -Go to step 38.
- Turn the ignition switch to LOCK (0).
- Check the No. 2 IG MAIN (50 A) fuse in the under- hood fuse/relay box.
Is the fuse OK?
YES -Repair open in the wire between the No. 2 IG MAIN (50 A) fuse and the ignition switch. If the wire is OK, go to step 40.
NO -Repair short in the wire between the No. 2 IG MAIN (50 A) fuse and the under-hood fuse/relay box. Also replace the No. 2 IG MAIN (50 A) fuse.
- Inspect the No. 19 Fl MAIN (15 A) fuse in the under- hood fuse/relay box.
Is the fuse OK?
YES -Go to step 47.
NO -Go to step 41.
- Remove the blown No. 19 Fl MAIN (15 A) fuse from the under-hood fuse/relay box.
- Remove PGM-FI main relay 1 (C) from the under- hood fuse/relay box.
- Check for continuity between body ground and PGM-FI main relay 1 4P connector terminals No. 1 and No. 3 individually.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Replace the under-hood fuse/relay box (see REMOVAL AND INSTALLATION ). Also replace the No. 19 Fl MAIN (15 A) fuse.
NO -Go to step 44.
- Disconnect each of the components or connectors from these components, one at a time, and check for continuity between PGM-FI main relay 1 4P connector terminal No. 2 and body ground.
- PGM-FI main relay 2 (FUEL PUMP)
- ECM connector A (44P)
- Each injector 2P connector
- Camshaft position (CMP) sensor B 3P connector
- Crankshaft position (CKP) sensor 3P connector
- Ignition coil relay
- Electronic throttle control system (ETCS) control relay
Does continuity go away when one of the above components is disconnected?
YES -Replace the component that made the short to body ground go away when disconnected. Reconnect all connectors, then update the ECM if it does not have the latest software (see ECM UPDATE ), or substitute a known-good ECM (see SUBSTITUTING THE ECM ), then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM (see ECM REPLACEMENT ). Also replace the No. 19 Fl MAIN (15 A) fuse.
NO -Go to step 45.
- Disconnect the connectors from these components:
- PGM-FI main relay 2 (FUEL PUMP)
- ECM connector A (44P)
- Injectors
- Camshaft position (CMP) sensor B
- Crankshaft position (CKP) sensor
- Ignition coil relay
- Electronic throttle control system (ETCS) control relay
- Check for continuity between PGM-FI main relay 1 4P connector terminal No. 2 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Repair short in the wire between PGM-FI main relay 1 and each item. Also replace the No. 19 FI MAIN (15A) fuse.
NO -Replace PGM-FI main relay 1. Also replace the No. 19 Fl MAIN (15 A) fuse.
- Inspect the No. 2 FUEL PUMP (15 A) fuse in the under-dash fuse/relay box.
Is the fuse OK?
YES -Go to step 58.
NO -Go to step 48.
- Remove the blown No. 2 FUEL PUMP (15 A) fuse from the under-dash fuse/relay box.
- Remove PGM-FI main relay 2 (FUEL PUMP) (A) from the under-dash fuse/relay box.
- Test PGM-FI main relay 2 (FUEL PUMP) (see POWER RELAY TEST
).
Is the relay OK?
YES -Go to step 51.
NO -Replace PGM-FI main relay 2 (FUEL PUMP). Also replace the No. 2 FUEL PUMP (15 A) fuse.
- Check for continuity between PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 1 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Go to step 52.
NO -Go to step 54.
- Jump the SCS line with the HDS, then disconnect ECM connector C (44P).
- Check for continuity between ECM connector terminal C36 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Repair short in the wire between the No. 2 FUEL PUMP (15 A) fuse and the ECM (C36), between the No. 2 FUEL PUMP (15 A) fuse and PGM-FI main relay 2 (FUEL PUMP), or between the No. 2 FUEL PUMP (15 A) fuse and the immobilizer control unit. Also replace the No. 2 FUEL PUMP (15 A) fuse.
NO -Replace the No. 2 FUEL PUMP (15 A) fuse, and update the ECM if it does not have the latest software (see ECM UPDATE ), or substitute a known- good ECM (see SUBSTITUTING THE ECM ), then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM (see ECM REPLACEMENT ).
- Remove the rear cushion seat (see SEAT CUSHION ).
- Remove the rear floor upper cross-member, and the access panel from the floor (see FUEL TANK UNIT REMOVAL/INSTALLATION ).
- Disconnect the fuel pump 4P connector.
- Check for continuity between fuel pump 4P connector terminal No. 2 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Repair short in the wire between the fuel pump and PGM-FI main relay 2 (FUEL PUMP). Also replace the No. 2 FUEL PUMP (15 A) fuse.
NO -Check the fuel pump, and replace it if needed (see FUEL PUMP/FUEL GAUGE SENDING UNIT REPLACEMENT ). Also replace the No. 2 FUEL PUMP (15 A) fuse.
- Jump the SCS line with the HDS.
- Disconnect ECM connectors A (44P) and C (44P).
- Turn the ignition switch to ON (II).
- Measure the voltage between ECM connector terminal C36 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES -Go to step 62.
NO -Repair open in the wire between the No. 2 FUEL PUMP (15 A) fuse and the ECM (C36).
- Measure the voltage between ECM connector terminal A6 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES -Go to step 67.
NO -Go to step 63.
- Turn the ignition switch to LOCK (0).
- Remove PGM-FI main relay 1 (C) from the under- hood fuse/relay box.
- Measure the voltage between PGM-FI main relay 1 4P connector terminal No. 3 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES -Go to step 66.
NO -Replace the under-hood fuse/relay box (see REMOVAL AND INSTALLATION ).
- Check for continuity between PGM-FI main relay 1 4P connector terminal No. 4 and ECM connector terminal A6.Fig 19: Checking Continuity Between PGM-FI Main Relay 1 4P Connector Terminal 4 And ECM Connector Terminal A6
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Test PGM-FI main relay 1 (see POWER RELAY TEST ). If the relay is OK, update the ECM if it does not have the latest software (see ECM UPDATE ), or substitute a known-good ECM (see SUBSTITUTING THE ECM ), then recheck. If the symptom/indication goes away with a known- good ECM, replace the original ECM (see ECM REPLACEMENT ).
NO -Repair open in the wire between the ECM (A6) and PGM-FI main relay 1.
- Turn the ignition switch to LOCK (0).
- Remove PGM-FI main relay 1 (C) from the under- hood fuse/relay box.
- Measure the voltage between PGM-FI main relay 1 4P connector terminal No. 1 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES -Go to step 70.
NO -Replace the under-hood fuse/relay box (see REMOVAL AND INSTALLATION ).
- Check for continuity between PGM-FI main relay 1 4P connector terminal No. 2 and ECM connector terminal A8.Fig 22: Checking Continuity Between PGM-FI Main Relay 1 4P Connector Terminal 2 And ECM Connector Terminal A8
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Go to step 71.
NO -Repair open in the wire between the ECM (A8) 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 connector B (44P).
- Check for continuity between body ground and ECM connector terminals B1, B36, C2, C40, and C44 individually.Fig 23: Checking Continuity Between Body Ground And ECM Connector Terminals B1, B36, C2, C40, And C44
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Go to step 74.
NO -Repair open in the wire between the ECM (B1, B36, C2, C40, C44) and G101 (see ENGINE WIRE HARNESS (SI MODEL) ).
- Check for continuity between ECM connector terminal C13 and body ground.
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Is there continuity?
YES -Go to step 75.
NO -Go to step 76.
- Continue to check for continuity between ECM connector terminal C13 and body ground, while disconnecting the MAP sensor 3P connector.
Is there continuity?
YES -Repair short in the wire between the ECM (C13) and the MAP sensor.
NO -Replace the MAP sensor (see MAP SENSOR REPLACEMENT ).
- Check for continuity between ECM connector terminal B18 and body ground.
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Is there continuity?
YES -Go to step 77.
NO -Go to step 78.
- Continue to check for continuity between ECM connector terminal B18 and body ground, while disconnecting the output shaft (countershaft) speed sensor 3P connector.
Is there continuity?
YES -Repair short in the wire between the ECM (B18) and the output shaft (countershaft) speed sensor.
NO -Replace the output shaft (countershaft) speed sensor (see OUTPUT SHAFT (COUNTERSHAFT) SPEED SENSOR REPLACEMENT ).
- Check for continuity between ECM connector terminal C12 and body ground.
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Is there continuity?
YES -Go to step 79.
NO -Go to step 80.
- Continue to check for continuity between ECM 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 (C12) and the throttle body.
NO -Replace the throttle body (see THROTTLE BODY REMOVAL/INSTALLATION ).
- Check for continuity between ECM connector terminal A25 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Go to step 81.
NO -Go to step 82.
- Continue to check for continuity between ECM 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 (A25) and the APP sensor.
NO -Replace the accelerator pedal module (see ACCELERATOR PEDAL MODULE REMOVAL/INSTALLATION ).
- Check for continuity between ECM connector terminal A24 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Go to step 83.
NO -Go to step 84.
- Continue to check for continuity between ECM connector terminal A24 and body ground, while disconnecting the APP sensor 6P connector.
Is there continuity?
YES -Repair short in the wire between the ECM (A24) and the APP sensor.
NO -Replace the accelerator pedal module (see ACCELERATOR PEDAL MODULE REMOVAL/INSTALLATION ).
- Check for continuity between ECM connector terminal A19 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Go to step 85.
NO -Reconnect all connectors, then update the ECM if it does not have the latest software (see ECM UPDATE ), or substitute a known-good ECM (see SUBSTITUTING THE ECM ), then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM (see ECM REPLACEMENT ).
- Continue to check for continuity between ECM connector terminal A19 and body ground, while disconnecting these connectors, one at a time:
- A/C pressure sensor 3P connector
- FTP sensor 3P connector
Does continuity go away when one of the above components is disconnected?
YES -Replace the part that caused an open when it was disconnected.
NO -Repair short in the wire between the ECM (A19) and the A/C pressure sensor or the FTP sensor.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.