DLC Circuit Troubleshooting - PGM-FI System
NOTE: Make sure the HDS and its DLC cable are working properly.
  1. Turn the ignition switch to LOCK (0).
  1. Connect the HDS to the DLC.
    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 21 .
  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 EPS system, go to Step 9 .
  • If the HDS does not communicate with the IMMOBI (immobilizer) system, go to Step 11 .
  • If the HDS does not communicate with the BODY ELECTRICAL system, go to Step 13 .
  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 13 .
  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 13 .
  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 13 .
  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 13 .
Are any B-CAN DTCs indicated?
YES -
Go to the indicated DTC's troubleshooting.■
NO -
Go to Step 14 .
  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 17 .
NO -
Go to Step 18 .
  1. 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 (28P)
    • VSA modulator-control unit 37P connector
    • EPS control unit connector D (28P)
    • Immobilizer-keyless control unit 7P connector
    • Audio unit 17P connector
    • Under-dash fuse/relay box connector Q (16P)
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 VSA modulator-control unit, the SRS unit, the EPS control unit, the immobilizer-keyless control unit, the audio unit, or the 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 (28P)
    No. 24 (LT BLU)
    VSA modulator-control unit 37P
    No. 26 (LT BLU)
    EPS control unit D (28P)
    No. 17 (LT BLU)
    Immobilizer-keyless control unit 7P
    No. 5 (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 DLC terminal and each of the terminals in the chart?
YES -
Replace the part that does not communicate with HDS.■
NO -
Repair open in the wire between the DLC (K-line) and the appropriate connector.■
Is DTC B1168, B1169, and/or B1178 indicated?
YES -
Go to Step 33 .
NO -
Go to Step 21 .
  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 24 .
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.■
  1. Measure the voltage between DLC terminals No. 4 and No. 16.
Is there battery voltage?
YES -
Go to Step 25 .
NO -
Repair open in the wire between DLC terminal No. 4 and body ground (G503).■
  1. Connect the HDS to the DLC.
  1. Jump the SCS line with the HDS.
  1. Disconnect ECM 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 connector terminal A3 and body ground.
Is there continuity?
YES -
Go to Step 31 .
NO -
Repair open in the wire between the ECM (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 connector terminal A4 and body ground.
Is there continuity?
YES -
Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM. ■
NO -
Repair open in the wire between the ECM (A4) and DLC terminal No. 14.■
  1. Try to start the engine.
Does the engine start and idle smoothly?
YES -
NO -
Go to Step 34 .
  1. Turn the ignition switch to LOCK (0).
  1. 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 36 .
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.■
  1. Check the No. 9 IGP (15 A) fuse in the under-hood fuse/relay box.
Is the fuse OK?
YES -
Go to Step 43 .
NO -
Go to Step 37 .
  1. Jump the SCS line with the HDS.
  1. Disconnect ECM connector A (49P).
  1. Check for continuity between ECM connector terminal A9 and body ground.
Is there continuity?
YES -
Go to Step 40 .
NO -
Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM. Also replace the No. 9 IGP (15 A) fuse.■
  1. While disconnecting each of parts or connectors below, one at a time, check for continuity between the ECM connector terminal A9 and body ground.
    • PGM-FI main relay 2 (FUEL PUMP)
    • Each injector 2P connector
    • CKP sensor 3P connector
    • CMP sensor 3P connector
    • Under-hood fuse/relay box (white) connector D (20P)
Does continuity go away when one of the above part is disconnected?
YES -
Replace the part that made the short to body ground go away when disconnected. If the part is the ECM, update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM. Also replace the No. 9 IGP (15 A) fuse.■
NO -
Go to Step 41 .
  1. Disconnect these parts or connectors:
    • PGM-FI main relay 2 (FUEL PUMP)
    • Each injector 2P connector
    • CKP sensor 3P connector
    • CMP sensor 3P connector
    • Under-hood fuse/relay box (white) connector D (20P)
  1. Check for continuity between ECM connector terminal A9 and body ground.
Is there continuity?
YES -
Repair short in the wire between the ECM (A9) and each part. Also replace the No. 9 IGP (15 A) fuse.■
NO -
Replace the under-hood fuse/relay box. Also replace the No. 9 IGP (15 A) fuse.■
  1. Check the No. 2 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 44 .
  1. Remove the blown No. 2 FUEL PUMP (15 A) fuse in the under-dash fuse/relay box.
  1. Remove PGM-FI main relay 2 (FUEL PUMP) (A) from the under-dash fuse/relay box.
Is the relay OK?
YES -
Go to Step 47 .
NO -
Replace the PGM-FI main relay 2 (FUEL PUMP). Also replace the No. 2 FUEL PUMP (15 A) fuse.■
  1. Check for continuity between PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 2 and body ground.
Is there continuity?
YES -
Go to Step 48 .
NO -
Go to Step 51 .
  1. Jump the SCS line with the HDS.
  1. Disconnect ECM connector C (49P).
  1. Check for continuity between ECM connector terminal C10 and body ground.
Is there continuity?
YES -
Repair short in the wire between the No. 2 FUEL PUMP (15 A) fuse and the ECM (C10), 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-keyless 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, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM. ■
  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 PGM-FI main relay 2 (FUEL PUMP) and the fuel pump. Also replace the No. 2 FUEL PUMP (15 A) fuse.■
NO -
Go to Step 54 .
  1. Reinstall PGM-FI main relay 2 (FUEL PUMP) (A) to the under-dash fuse/relay box.
  1. Check for continuity between fuel pump 4P connector terminal No. 2 and body ground.
Is there continuity?
YES -
Replace 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. Also replace the No. 2 FUEL PUMP (15 A) fuse.■
  1. Remove the battery.
  1. Disconnect ECM connector A (49P) and C (49P).
  1. Connect a battery.
  1. Turn the ignition switch to ON (II).
  1. Measure the voltage between ECM connector terminal C10 and body ground.
Is there battery voltage?
YES -
Go to Step 61 .
NO -
Repair open in the wire between the ECM (C10) and the No. 2 FUEL PUMP (15 A) fuse.■
  1. Measure the voltage between ECM connector terminal A7 and body ground.
Is there battery voltage?
YES -
Go to Step 66 .
NO -
Go to Step 62 .
  1. Turn the ignition switch to LOCK (0).
  1. Disconnect a battery.
  1. Check for continuity between ECM connector terminal A7 and under-hood fuse/relay box connector D (20P) terminal No. 16.
Is there continuity?
YES -
NO -
Repair open in the wire between the ECM (A7) and the under-hood fuse/relay box.■
  1. Turn the ignition switch to LOCK (0).
  1. Disconnect the battery.
  1. Disconnect under-hood fuse/relay box (white) connector D (20P).
  1. Check for continuity between ECM connector terminal A9 and under-hood fuse/relay box (white) connector D (20P) terminal No. 5.
Is there continuity?
YES -
Go to Step 70 .
NO -
Repair open in the wire between the ECM (A9) and the under-hood fuse/relay box.■
Is the relay OK?
YES -
Go to Step 66 .
NO -
  1. Disconnect ECM connector B (49P).
  1. Check for continuity between body ground and ECM connector terminals B1, B10, C2, C44, and C48 individually.
Is there continuity?
YES -
Go to Step 73 .
NO -
Repair open in the wire between the ECM (B1, B10, C2, C44, C48) and G101.■
  1. Check for continuity between ECM connector terminal C13 and body ground.
Is there continuity?
YES -
Go to Step 74 .
NO -
Go to Step 75 .
  1. Continue to check for continuity between ECM connector terminal C13 and body ground, while disconnecting these parts, one at a time:
    • MAP sensor 3P connector
    • Output shaft (countershaft) speed 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 (C13) and the MAP sensor, the output shaft (countershaft) speed sensor.■
  1. Check for continuity between ECM connector terminal B19 and body ground.
Is there continuity?
YES -
Go to Step 76 .
NO -
Go to Step 77 .
  1. Continue to check for continuity between ECM connector terminal B19 and body ground, while disconnecting the EGR valve 5P connector.
Does continuity go away when the components is disconnected?
YES -
NO -
Repair short in the wire between the ECM (B19) and the EGR valve.■
  1. Check for continuity between ECM connector terminal C12 and body ground.
Is there continuity?
YES -
Go to Step 78 .
NO -
Go to Step 79 .
  1. 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 -
  1. Check for continuity between ECM connector terminal A26 and body ground.
Is there continuity?
YES -
Go to Step 80 .
NO -
Go to Step 81 .
  1. Continue to check for continuity between ECM 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 (A26) and APP sensor A.■
NO -
  1. Check for continuity between ECM connector terminal A25 and body ground.
Is there continuity?
YES -
Go to Step 82 .
NO -
Go to Step 83 .
  1. 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 APP sensor B.■
NO -
  1. Check for continuity between ECM connector terminal A20 and body ground.
Is there continuity?
YES -
Go to Step 84 .
NO -
Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM. ■
  1. Continue to check for continuity between ECM 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 (A20) and the A/C pressure sensor.■
NO -