DLC Circuit Troubleshooting - PGM-FI System
NOTE: Make sure the HDS and the DLC cable of the HDS is normal.
  1. Turn the ignition switch OFF.
  1. NOTE: Make sure the HDS is properly connected to the DLC.
  1. Turn the ignition switch 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 -
Go to Step 5 .
  1. Turn the ignition switch OFF.
  1. Turn the ignition switch ON (II), and watch the SRS indicator.
Does the SRS indicator stay on?
YES -
NO -
Go to Step 7 .
  1. Turn the ignition switch OFF.
  1. Turn the ignition switch ON (II), and watch the VSA indicator.
Does the VSA indicator stay on?
YES -
NO -
Go to Step 9 .
  1. Turn the ignition switch OFF.
  1. Turn the ignition switch ON (II), and watch the EPS indicator.
Does the EPS indicator stay on?
YES -
NO -
Go to Step 11 .
  1. Turn the ignition switch OFF.
  1. Turn the ignition switch 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 15 .
  1. Turn the ignition switch OFF.
  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 18 .
NO -
Go to Step 19 .
  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 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 (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 VSA control unit, the SRS unit, the EPS control unit, the immobilizer control unit-receiver, 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 control unit 37P
    No. 26 (LT BLU)
    EPS control unit D (28P)
    No. 17 (LT BLU)
    Immobilizer control unit-receiver 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 unit which cannot 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 35 .
NO -
Go to Step 23 .
  1. Turn the ignition switch OFF.
  1. Disconnect the HDS from the DLC.
  1. Measure voltage between DLC terminal No. 16 and body ground.
Is there battery voltage?
YES -
Go to Step 26 .
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 voltage between DLC terminals No. 4 and No. 16.
Is there battery voltage?
YES -
Go to Step 27 .
NO -
Repair open in the wire between DLC terminal No. 4 and body ground (G503).■
  1. Jump the SCS line with the HDS.
  1. Disconnect ECM connector A (44P).
  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 A36 and body ground.
Is there continuity?
YES -
Go to Step 33 .
NO -
Repair open in the wire between the ECM (A36) 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 A37 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 (A37) and DLC terminal No. 14.■
  1. Try to start the engine.
Does the engine start and idle smoothly?
YES -
NO -
Go to Step 36 .
  1. Turn the ignition switch OFF.
  1. Check the No. 2 IG MAIN (50 A) fuse in the under-hood fuse/relay box.
Is the fuse OK?
YES -
Repair short in the wire the No. 2 IG MAIN (50 A) fuse and the ignition switch. If the wire is OK, go to Step 38 .
NO -
Repair short in the wire 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 39 .
  1. Remove the battery.
  1. Disconnect ECM connector A (44P).
  1. Check for continuity between ECM connector terminal A8 and body ground.
Is there continuity?
YES -
Go to Step 42 .
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. Continue to check for continuity between ECM connector terminal A8 and body ground, while disconnecting these parts, one at a time:
    • PGM-FI main relay 2 (FUEL PUMP)
    • Each injector 2P connector
    • CKP sensor 3P connector
    • CMP sensor 3P connector
    • Under-hood fuse/relay box 20P (white) 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. Also replace the No. 9 IGP (15 A) fuse.■
NO -
Repair short in the wire between the ECM (A8) and PGM-FI main relay 2 (FUEL PUMP), the injector, the CKP sensor, the CMP sensor, or 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 battery.
  1. Disconnect ECM connector C (44P).
  1. Check for continuity between ECM connector terminal C36 and body ground.
Is there continuity?
YES -
Go to Step 47 .
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. 2 FUEL PUMP (15 A) fuse.■
  1. Remove PGM-FI main relay 2 (FUEL PUMP) (A) from the under-dash fuse/relay box.
  1. Check for continuity between ECM connector terminal C36 and body ground.
Is there continuity?
YES -
Repair open in the wire between the ECM (C9) and the No. 2 FUEL PUMP (15 A) fuse, between the No. 2 FUEL PUMP (15 A) fuse and PGM-FI main relay 2 (FUEL PUMP), or between the immobilizer control unit. Also replace the No. 2 FUEL PUMP (15 A) fuse.■
NO -
Go to Step 49 .
  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 52 .
  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 necessary. Also replace the No. 2 FUEL PUMP (15 A) fuse.■
  1. Remove the battery.
  1. Disconnect ECM connector A (44P) and C (44P).
  1. Connect a battery.
  1. Turn the ignition switch ON (II).
  1. Measure voltage between ECM connector terminal C36 and body ground.
Is there battery voltage?
YES -
Go to Step 59 .
NO -
Repair open in the wire between the ECM (C36) and the No. 2 FUEL PUMP (15 A) fuse.■
  1. Measure voltage between ECM connector terminal A6 and body ground.
Is there battery voltage?
YES -
Go to Step 64 .
NO -
Go to Step 60 .
  1. Turn the ignition switch OFF.
  1. Disconnect a battery.
  1. Check for continuity between ECM connector terminal A6 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 (A6) and the under-hood fuse/relay box.■
  1. Turn the ignition switch OFF.
  1. Disconnect a battery.
  1. Check for continuity between ECM connector terminal A8 and under-hood fuse/relay box connector D (20P) terminal No. 5.
Is there continuity?
YES -
Go to Step 68 .
NO -
Repair open in the wire between the ECM (A6) and the under-hood fuse/relay box.■
Is PGM-FI main relay 1 OK?
YES -
Go to Step 69 .
NO -
  1. Disconnect ECM connector B (44P).
  1. Check for continuity between body ground and ECM connector terminals B1, B36, C2, C40, and C44 individually.
Is there continuity?
YES -
Go to Step 71 .
NO -
Repair open in the wire between the ECM (B1, B36, C2, C40, C44) and G101. ■
  1. Check for continuity between ECM connector terminal C13 and body ground.
Is there continuity?
YES -
Go to Step 72 .
NO -
Go to Step 73 .
  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
    • EOP 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 EOP sensor, the output shaft (countershaft) speed sensor.■
  1. Check for continuity between ECM connector terminal B18 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 B18 and body ground, while disconnecting these parts, one at a time:
    • IMT actuator 5P connector
    • EGR valve 6P 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 (B18) and the IMT actuator, the EGR valve.■
  1. Check for continuity between ECM connector terminal C12 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 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 A25 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 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 A.■
NO -
  1. Check for continuity between ECM connector terminal A24 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 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 APP sensor B.■
NO -
  1. Check for continuity between ECM connector terminal A19 and body ground.
Is there continuity?
YES -
Go to Step 82 .
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 A19 and body ground, while disconnecting the A/C pressure sensor 3P connector.
Is there continuity?
YES -
Repair short in the wire between the ECM (A19) and the A/C pressure sensor.■
NO -