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.

Turn the ignition switch to LOCK (0).
Connect the HDS to the DLC (see GENERAL TROUBLESHOOTING INFORMATION ).
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 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 ABS system, 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 system, 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 an SRS indicator that comes on with no stored DTCs (see SYMPTOM TROUBLESHOOTING INDEX ).
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 symptom troubleshooting for an ABS indicator, brake system indicator, and VSA indicator that do not go off (see SYMPTOM TROUBLESHOOTING INDEX ).
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 an ABS indicator and a brake system indicator that do not go off (see SYMPTOM TROUBLESHOOTING INDEX ).
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 symptom troubleshooting for an EPS indicator that does not go off with no stored DTCs (see SYMPTOM TROUBLESHOOTING INDEX ).
Turn the ignition switch to LOCK (0).
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 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 INDEX ).

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.

NO -Go to step 19.
Turn the ignition switch to LOCK (0), then do the 12 volt battery terminal disconnection procedure (see 12 VOLT 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.

Fig 1: Checking Continuity Between DLC Terminal No. 7 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there 5 Ω or less?

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 parts, one at a time:
- SRS unit connector A (39P)
- VSA modulator-control unit 47P connector
- ABS 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 24P connector
- Under-dash fuse/relay box connector Q (16P)
Does continuity go away when one of the above parts is disconnected?

YES -Replace the part caused an open when it was disconnected.

NO -Repair a short in the wire between the DLC (K-line) and the VSA modulator-control unit, the ABS control unit, the SRS unit, the EPS control unit, the immobilizer-keyless control unit, the audio-navigation unit, or the under-dash fuse/relay box.
Connect DLC terminal No. 7 to body ground with a jumper wire.

Fig 2: Connecting DLC Terminal No. 7 To Body Ground With Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Check for continuity between body ground and these connector terminals:

CONTINUITY SPECIFICATION

Connector	Terminal
SRS unit A (39P)	No. 18 (BLU)
VSA control unit 47P	No. 10 (RED)
ABS control unit 47P	No. 10 (RED)
EPS control unit C(16P)	No. 16 (RED)
TPMS control unit 20P	No. 7 (BLU)
Immobilizer-keyless control unit 7P	No. 5 (BLU)
Audio-navigation 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 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.

Check for B-CAN system DTCs without the HDS (see GENERAL TROUBLESHOOTING INFORMATION ).
Is DTC U0029 and/or U0100 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.

Fig 3: Measuring Voltage Between DLC Terminal No. 16 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES -Go to step 29.

NO -Repair an 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.

Fig 4: Measuring Voltage Between DLC Terminals No. 4 And No. 16
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES -Go to step 30.

NO -Repair an open in the wire between DLC terminal No. 4 and body ground (G502) (see DASHBOARD WIRE HARNESS (VIEW OF MIDDLE SECTION) (WITH NAVIGATION) ).
Connect the HDS to the DLC (see GENERAL TROUBLESHOOTING INFORMATION ).
Jump the SCS line with the HDS.
Disconnect PCM connector A (44P).
Disconnect the HDS from the DLC.
Check for continuity between PCM connector terminal A36 and DLC terminal No. 6.

Fig 5: Checking Continuity Between PCM Connector Terminal A36 And DLC Terminal No. 6
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 35.

NO -Repair an open in the wire between the PCM (A36) and DLC terminal No. 6.
Check for continuity between PCM connector terminal A37 and DLC terminal No. 14.

Fig 6: Checking Continuity Between PCM Connector Terminal A37 And DLC Terminal No. 14
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Update the PCM if it does not have the latest software (see PCM UPDATE ), or substitute a known-good PCM (see SUBSTITUTING THE PCM ), then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM (see PCM REPLACEMENT ).

NO -Repair an open in the wire between the PCM (A37) and DLC terminal No. 14.
Try to start the engine.
Does the engine start and idle smoothly?

YES -Go to F-CAN circuit troubleshooting (see F-CAN CIRCUIT TROUBLESHOOTING ).

NO -Go to step 37.
Turn the ignition switch to LOCK (0).
Check the No. 60 IGSW (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 IGSW (50 A) fuse and the ignition switch. If the wire is OK go to step 39.

NO -Repair a short in the wire between the No. 60 IGSW (50 A) fuse and the under-dash fuse/relay box. Also replace the No. 60 IGSW (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-dash fuse/relay box.
Open the fuse access panel (A), then remove PGM-FI main relay 1 (B) from the under-dash fuse/relay box.

Fig 7: Identifying Fuse Access Panel And PGM-FI Main Relay 1
Courtesy of AMERICAN HONDA MOTOR CO., INC.
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 And 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 45.
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 (44P)
- Each injector 2P connector
- Camshaft position (CMP) sensor 3P connector
- Crankshaft position (CKP) sensor 3P connector
- Electronic throttle control system (ETCS) control relay
Fig 9: Checking Continuity Between PGM-FI Main Relay 1 4P Connector Terminal No. 1 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

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 (see PCM UPDATE ), or substitute a known-good PCM (see SUBSTITUTING THE PCM ), then recheck. If the symptom/indication goes away and the PCM was updated, troubleshooting is complete. If the symptom/indication goes away with a known-good PCM, replace the original PCM (see PCM REPLACEMENT ). Also replace the No. 39 IGP (15 A) fuse.

NO -Go to step 44.
Disconnect the connectors from these parts:
- PGM-FI main relay 2
- PCM connector A (44P)
- Each injector 2P connector
- CMP sensor 3P connector
- CKP sensor 3P connector
- Electronic throttle control (ETCS) control relay
Check for continuity between PGM-FI main relay 1 4P connector terminal No. 1 and body ground.

Fig 10: Checking Continuity Between PGM-FI Main Relay 1 4P Connector Terminal No. 1 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

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 (15A) 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.
Remove PGM-FI main relay 2 (A) from the auxiliary under-hood fuse/relay box.

Fig 11: Identifying PGM-FI Main Relay 2
Courtesy of AMERICAN HONDA MOTOR CO., INC.
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.

Fig 12: Checking Continuity Between PGM-FI Main Relay 2 4P Connector Terminal No. 2 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 51.

NO -Go to step 54.
Jump the SCS line with the HDS.
Disconnect PCM connector C (44P).
Check for continuity between PCM connector terminal C36 and body ground.

Fig 13: Checking Continuity Between PCM Connector Terminal C36 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Repair a short in the wire between the No. 20 FUEL PUMP (15 A) fuse and the PCM (C36) or PGM-FI main relay 2. Also replace the No. 20 FUEL PUMP (15A) fuse.

NO -Replace the No. 20 FUEL PUMP (15 A) fuse, and update the PCM if it does not have the latest software (see PCM UPDATE ), or substitute a known-good PCM (see SUBSTITUTING THE PCM ), then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM (see 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.

Fig 14: Checking Continuity Between Fuel Pump 4P Connector Terminal No. 2 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

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 (15A) fuse.

NO -Check the fuel pump, and replace it if needed (see FUEL PUMP/FUEL GAUGE SENDING UNIT REPLACEMENT ). Also replace the No. 20 FUEL PUMP (15 A) fuse.
Jump the SCS line with the HDS.
Disconnect PCM connectors A (44P) and C (44P).
Turn the ignition switch to ON (II).
Measure the voltage between PCM connector terminal C36 and body ground.

Fig 15: Measuring Voltage Between PCM Connector Terminal C36 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?

YES -Go to step 60.

NO -Repair an open in the wire between the No. 20 FUEL PUMP (15 A) fuse and the PCM (C36).
Measure the voltage between PCM connector terminal A6 and body ground.

Fig 16: Measuring Voltage Between PCM Connector Terminal A6 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

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 PGM-FI main relay 1 (B) from the under-dash fuse/relay box.

Fig 17: Identifying Fuse Access Panel And PGM-FI Main Relay 1
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Measure the voltage between PGM-FI main relay 1 4P connector terminal No. 3 and body ground.

Fig 18: Measuring 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 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.

Fig 19: Connecting PGM-FI Main Relay 1 4P Connector Terminal No. 4 To Body Ground With Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity between PCM connector terminal A6 and body ground.

Fig 20: Checking Continuity Between PCM Connector Terminal A6 And Body Ground
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 PCM if it does not have the latest software (see PCM UPDATE ), or substitute a known-good PCM (see SUBSTITUTING THE PCM ), then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM (see PCM REPLACEMENT ).

NO -Repair an open in the wire between the PCM (A6) and PGM-FI main relay 1.
Turn the ignition switch to LOCK (0).
Open the fuse access panel (A), then remove PGM-FI main relay 1 (B) from the under-dash fuse/relay box.

Fig 21: Identifying Fuse Access Panel And PGM-FI Main Relay 1
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Measure the voltage between PGM-FI main relay 1 4P connector terminal No. 2 and body ground.

Fig 22: Measuring Voltage Between PGM-FI Main Relay 1 4P Connector Terminal No. 2 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

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.

Fig 23: Connecting PGM-FI Main Relay 1 4P Connector Terminal No. 1 To Body Ground With Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Check for continuity between body ground and PCM connector terminals A8 and A43 individually.

Fig 24: Checking Continuity Between Body Ground And PCM Connector Terminals A8 And A43
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 71.

NO -Repair an open in the wire between the PCM (A8, A43) and PGM-FI main relay 1.
Disconnect PCM connector B (44P).
Check for continuity between body ground and PCM connector terminals B1, B36, C2, C40, and C44 individually.

Fig 25: Checking Continuity Between Body Ground And PCM Connector Terminals B1, B36, C2, C40, And C44
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 73.

NO -Repair an open in the wire between the PCM (B1, B36, C2, C40, C44) and G101 (see GROUND TO COMPONENTS INDEX ).
Check for continuity between PCM connector terminal C39 and body ground.

Fig 26: Checking Continuity Between PCM Connector Terminal C39 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 74.

NO -Go to step 75.
Continue to check for continuity between PCM connector terminal C39 and body ground, while disconnecting these parts, one at a time:
- MAP sensor 3P connector
- CVT output (driven pulley) speed sensor 3P connector
Does continuity go away when one of the above parts is disconnected?

YES -Replace the part that caused an open when it was disconnected.

NO -Repair a short in the wire between the PCM (C39) and the MAP sensor or the CVT output (driven pulley) speed sensor.
Check for continuity between PCM connector terminal B6 and body ground.

Fig 27: Checking Continuity Between PCM Connector Terminal B6 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 76.

NO -Go to step 77.
Continue to check for continuity between PCM connector terminal B6 and body ground, while disconnecting these parts, one at a time:
- Rocker arm oil pressure sensor A and B 3P connectors
- EGR valve 5P connector
- CVT input (drive pulley) speed sensor 3P connector
- Vehicle speed sensor 3P connector
Does continuity go away when one of the above parts is disconnected?

YES -Replace the part that caused an open when it was disconnected.

NO -Repair a short in the wire between the PCM (B6) and rocker arm oil pressure sensor A and B, the EGR valve, the CVT input (drive pulley) speed sensor, the CVT speed sensor.
Check for continuity between PCM connector terminal C12 and body ground.

Fig 28: Checking Continuity Between PCM Connector Terminal C12 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 78.

NO -Go to step 79.
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 (see THROTTLE BODY REMOVAL/INSTALLATION ).
Check for continuity between PCM connector terminal A25 and body ground.

Fig 29: Checking Continuity Between PCM Connector Terminal A25 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 80.

NO -Go to step 81.
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 A.

NO -Replace the accelerator pedal module (see ACCELERATOR PEDAL MODULE REMOVAL/INSTALLATION ).
Check for continuity between PCM connector terminal A24 and body ground.

Fig 30: Checking Continuity Between PCM Connector Terminal A24 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 82.

NO -Go to step 83.
Continue to check for continuity between PCM connector terminal A24 and body ground, while disconnecting the APP sensor 6P connector.
Is there continuity?

YES -Repair a short in the wire between the PCM (A24) and APP sensor B.

NO -Replace the accelerator pedal module (see ACCELERATOR PEDAL MODULE REMOVAL/INSTALLATION ).
Check for continuity between PCM connector terminal A19 and body ground.

Fig 31: Checking Continuity Between PCM Connector Terminal A19 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES -Go to step 84.

NO -Update the PCM if it does not have the latest software (see PCM UPDATE ), or substitute a known-good PCM (see SUBSTITUTING THE PCM ), then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM (see PCM REPLACEMENT ).
Continue to check for continuity between PCM connector terminal A19 and body ground, while disconnecting these parts, one at a time: