DLC Circuit Troubleshooting
NOTE: Make sure the HDS and the DLC cable of the HDS are not defective.
  1. Turn the ignition switch to LOCK (0).
  1. NOTE: Make sure the HDS is properly connected to the DLC.
  1. 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 .
  1. Check for Temporary DTCs or DTCs in the PGM-FI system with the HDS.
Are any Temporary DTCs or 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 Adaptive cruise control/Lane keeping assist system (with driving support 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 IMMOBI (immobilizer) system, go to Step 13 .
  • If the HDS does not communicate with the BODY ELECTRICAL system, go to Step 15 .
  1. Turn the ignition switch to LOCK (0).
  1. Turn the ignition switch to ON (II), and watch the SRS indicator.
Does the SRS indicator stay on?
YES -
NO -
Go to Step 17 .
  1. Turn the ignition switch to LOCK (0).
  1. Turn the ignition switch to ON (II), and watch the VSA indicator.
Does the VSA indicator stay on?
YES -
NO -
Go to Step 17 .
  1. Turn the ignition switch to LOCK (0).
  1. Turn the ignition switch to ON (II), and watch the ACC/LKAS indicator.
Does the ACC/LKAS indicator stay on?
YES -
NO -
Go to Step 17 .
  1. Turn the ignition switch to LOCK (0).
  1. Turn the ignition switch to ON (II), and watch the EPS indicator.
Does the EPS indicator stay on?
YES -
NO -
Go to Step 17 .
  1. Turn the ignition switch to LOCK (0).
  1. Turn the ignition switch to ON (II), and watch the immobilizer indicator.
Does the immobilizer indicator stay on or flash?
YES -
NO -
Go to Step 17 .
  1. Check the gauge display.
Is Error 2 indicated?
YES -
Check for B-CAN system DTCs.■
NO -
Go to Step 17 .
  1. Turn the ignition switch to LOCK (0).
  1. Disconnect the HDS from the DLC.
  1. Check for continuity between DLC terminal No. 7 and body ground.
Is there continuity?
YES -
Go to Step 20 .
NO -
Go to Step 21 .
  1. 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 47P connector
    • EPS control unit connector D (28P)
    • ACC unit 20P connector (with driving support system)
    • LKAS control unit 26P connector (with driving support system)
    • Immobilizer-keyless control unit 7P connector
    • Audio unit 24P connector
    • Driver's under-dash fuse/relay box connector Q (20P)
Does continuity go away when one of the above connectors 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 VSA modulator-control unit, the EPS control unit, the SRS unit, the ACC unit (with driving support system), the LKAS control unit (with driving support system), the immobilizer-keyless control unit, the audio unit, or the driver's under-dash fuse/relay box.■
  1. Connect DLC terminal No. 7 to body ground with a jumper wire.
  1. Check for continuity between body ground and these connector terminals:
    Connector
    Terminal
    SRS unit A (39P)
    No. 18 (LT BLU)
    VSA modulator-control unit 47P
    No. 10 (LT BLU)
    EPS control unit D connector (28P)
    No. 17 (LT BLU)
    ACC unit 20P connector (with driving support system)
    No. 8 (LT BLU)
    LKAS control unit 26P connector (with driving support system)
    No. 9 (LT BLU)
    Immobilizer-keyless control unit 7P
    No. 5 (LT BLU)
    Audio unit 24P
    No. 3 (LT BLU)
    Driver's under-dash fuse/relay box Q (20P)
    No. 16 (LT 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 open in the wire between the DLC (K-line) and the appropriate connector.■
Is DTC U0029 and/or U0100 indicated?
YES -
Go to Step 36 .
NO -
Go to Step 24 .
  1. Turn the ignition switch to LOCK (0).
  1. Disconnect the HDS from the DLC.
  1. Measure the voltage between DLC terminal No. 16 and body ground.
Is there battery voltage?
YES -
Go to Step 27 .
NO -
Repair open in the wire between DLC terminal No. 16 and the No. 15 BACK UP (10 A) fuse in the under-hood fuse/relay box.■
  1. Measure the voltage between DLC terminals No. 4 and No. 16.
Is there battery voltage?
YES -
Go to Step 28 .
NO -
Repair open in the wire between DLC terminal No. 4 and body ground (G501). ■
  1. Jump the SCS line with the HDS.
  1. Disconnect ECM/PCM connector A (49P).
  1. Disconnect the HDS from the DLC.
  1. Connect DLC terminal No. 6 to body ground with a jumper wire.
  1. Check for continuity between ECM/PCM connector terminal A3 and body ground.
Is there continuity?
YES -
Go to Step 34 .
NO -
Repair open in the wire between the ECM/PCM (A3) and DLC terminal No. 6.■
  1. Connect DLC terminal No. 14 to body ground with a jumper wire.
  1. Check for continuity between ECM/PCM connector terminal A4 and body ground.
Is there continuity?
YES -
NO -
Repair open in the wire between the ECM/PCM (A4) and DLC terminal No. 14.■
  1. Try to start the engine.
Does the engine start and idle smoothly?
YES -
NO -
Go to Step 37 .
  1. Turn the ignition switch to LOCK (0).
  1. Check the No. 3 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. 3 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. 3 IG MAIN (50 A) fuse and the ignition switch. Also replace the No. 3 IG MAIN (50 A) fuse.■
  1. Inspect the No. 17 FI MAIN (15 A) fuse in the under-hood fuse/relay box.
Is the fuse OK?
YES -
Go to Step 46 .
NO -
Go to Step 40 .
  1. Remove the blown No. 17 FI MAIN (15 A) fuse from the under-hood fuse/relay box.
  1. Remove PGM-FI main relay 1 (A) from the under-hood fuse/relay box.
  1. Check for continuity between body ground and PGM-FI main relay 1 4P connector terminals No. 1 and No. 4 individually.
Is there continuity?
YES -
Replace the under-hood fuse/relay box. Also replace the No. 17 FI MAIN (15 A) fuse.■
NO -
Go to Step 43 .
  1. 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. 2 and body ground.
    • PGM-FI main relay 2 (FUEL PUMP)
    • ECM/PCM connector A (49P)
    • Each injector 2P connector
    • Camshaft position (CMP) sensor B 3P connector
    • Crankshaft position (CKP) sensor 3P connector
    • MAF/IAT sensor 5P connector
    • Electronic throttle control system (ETCS) control relay
Does continuity go away when one of the above parts or connectors 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, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM. Also replace the No. 17 FI MAIN (15 A) fuse.■
NO -
Go to Step 44 .
  1. Disconnect these parts or connectors:
    • PGM-FI main relay 2 (FUEL PUMP)
    • ECM/PCM connector A (49P)
    • Injectors
    • Camshaft position (CMP) sensor B
    • MAF/IAT sensor
    • Crankshaft position (CKP) sensor
    • Electronic throttle control system (ETCS) control relay
  1. Check for continuity between PGM-FI main relay 1 4P connector terminal No. 2 and body ground.
Is there continuity?
YES -
Repair short in the wire between PGM-FI main relay 1 and each part. Also replace the No. 17 FI MAIN (15 A) fuse.■
NO -
Replace PGM-FI main relay 1. Also replace the No. 17 FI MAIN (15 A) fuse.■
  1. Inspect the No. 9 FUEL PUMP (20 A) fuse in the driver's under-dash fuse/relay box.
Is the fuse OK?
YES -
Go to Step 58 .
NO -
Go to Step 47 .
  1. Remove the blown No. 9 FUEL PUMP (20 A) fuse in the driver's under-dash fuse/relay box.
  1. Jump the SCS line with the HDS.
  1. Disconnect ECM/PCM connector C (49P).
  1. Check for continuity between ECM/PCM connector terminal C10 and body ground.
Is there continuity?
YES -
Go to Step 51 .
NO -
Replace the No. 9 FUEL PUMP (20 A) fuse, and update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM. ■
  1. Remove PGM-FI main relay 2 (FUEL PUMP) (A) from the driver's under-dash fuse/relay box.
  1. Check for continuity between ECM/PCM connector terminal C10 and body ground.
Is there continuity?
YES -
Repair short in the wire between the No. 9 FUEL PUMP (20 A) fuse and the ECM/PCM (C10), between the No. 9 FUEL PUMP (20 A) fuse and PGM-FI main relay 2 (FUEL PUMP), or between the No. 9 FUEL PUMP (20 A) fuse and the immobilizer control unit. Also replace the No. 9 FUEL PUMP (20 A) fuse.■
NO -
Go to Step 53 .
  1. Disconnect the fuel pump 4P connector.
  1. 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 (FUEL PUMP). Also replace the No. 9 FUEL PUMP (20 A) fuse.■
NO -
Go to Step 57 .
Is the relay OK?
YES -
Check the fuel pump, and replace it if necessary. Also replace the No. 9 FUEL PUMP (20 A) fuse.■
NO -
Replace PGM-FI main relay 2 (FUEL PUMP). Also replace the No. 9 FUEL PUMP (20 A) fuse.■
  1. Jump the SCS line with the HDS.
  1. Disconnect ECM/PCM connectors A (49P) and C (49P).
  1. Turn the ignition switch to ON (II).
  1. Measure the voltage between ECM/PCM connector terminal C10 and body ground.
Is there battery voltage?
YES -
Go to Step 62 .
NO -
Repair open in the wire between the No. 9 FUEL PUMP (20 A) fuse and the ECM/PCM (C10).■
  1. Measure the voltage between ECM/PCM connector terminal A7 and body ground.
Is there battery voltage?
YES -
Go to Step 67 .
NO -
Go to Step 63 .
  1. Turn the ignition switch to LOCK (0).
  1. Remove PGM-FI main relay 1 (A) from the under-hood fuse/relay box.
  1. Measure the voltage between PGM-FI main relay 1 4P connector terminal No. 4 and body ground.
Is there battery voltage?
YES -
Go to Step 66 .
NO -
  1. Check for continuity between PGM-FI main relay 1 4P connector terminal No. 3 and ECM/PCM connector terminal A7.
Is there continuity?
YES -
NO -
Repair open in the wire between the ECM/PCM (A7) and PGM-FI main relay 1.■
  1. Turn the ignition switch to LOCK (0).
  1. Remove PGM-FI main relay 1 (A) from the under-hood fuse/relay box.
  1. Measure the voltage between PGM-FI main relay 1 4P connector terminal No. 1 and body ground.
Is there battery voltage?
YES -
Go to Step 70 .
NO -
  1. Check for continuity between PGM-FI main relay 1 4P connector terminal No. 2 and ECM/PCM connector terminal A9.
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.■
Is PGM-FI main relay 1 OK?
YES -
Go to Step 72 .
NO -
Replace PGM-FI main relay 1 .■
  1. Disconnect ECM/PCM connector B (49P).
  1. 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; A/T, M/T. ■
  1. Check for continuity between ECM/PCM connector terminal C13 and body ground.
Is there continuity?
YES -
Go to Step 75 .
NO -
  1. 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 connectors is disconnected?
YES -
Replace the part that caused an open when it was disconnected.■
NO -
Repair short in the wires between the ECM/PCM (C13) and the MAP sensor or the output shaft (countershaft) speed sensor.■
  1. Check for continuity between PCM connector terminal B19 and body ground.
Is there continuity?
YES -
Go to Step 77 .
NO -
Go to Step 78 .
  1. Continue to check for continuity between PCM connector terminal B19 and body ground while disconnecting the input shaft (mainshaft) speed sensor 3P connector.
Is there continuity?
YES -
Repair short in the wire between the PCM (B19) and the input shaft (mainshaft) speed sensor.■
NO -
  1. 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 .
  1. 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 -
  1. 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 .
  1. 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 -
  1. 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 .
  1. 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 -
  1. Check for continuity between ECM/PCM connector terminal A20 and body ground.
Is there continuity?
YES -
Go to Step 85 .
NO -
  1. Continue to check for continuity between ECM/PCM connector terminal A20 and body ground while disconnecting the A/C pressure sensor 3P connector.
Is there continuity?
YES -
Repair short in the wire between the ECM/PCM (A20) and the A/C pressure sensor.■
NO -
Replace the A/C pressure sensor.■