DLC Circuit Troubleshooting

NOTE: Make sure the HDS and the DLC cable are in good operating condition.

1.Turn the ignition switch OFF.

2.Connect the HDS to the DLC.

NOTE: Make sure the HDS is properly connected to the DLC.

3.Turn the ignition switch ON (II), and turn on the HDS.

Does the HDS identify the vehicle?


YES - Go to 4.


NO - Go to 20.


4.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.n


NO - Go to 5.


5.Turn the ignition switch OFF.

6.Turn the ignition switch ON (II), and watch the SRS indicator.

Does the SRS indicator stay on?


YES - Go to the SRS system's general troubleshooting information.n


NO - Go to 7.

7.Turn the ignition switch OFF.

8.Turn the ignition switch ON (II), and watch the VSA indicator.

Does the VSA indicator stay on?


YES - Go to the VSA system's general troubleshooting information.n


NO - Go to 9.


9.Turn the ignition switch OFF.

10.Turn the ignition switch ON (II), and watch the EPS indicator.

Does the EPS indicator stay on?


YES - Go to the EPS system's general troubleshooting information.n


NO - Go to 11.


11.Turn the ignition switch OFF.

12.Turn the ignition switch ON (II), and watch the immobilizer indicator.

Does the immbilizer indicator stay on or flash?


YES - Go to the immobilizer system's troubleshooting.n


NO - Go to 13.

13.Do the gauge self-diagnostic function.

14.Check for B-CAN system DTCs without the HDS.

Are any B-CAN DTCs indicated?


YES - Go to the indicated DTC's troubleshooting.n


NO - Go to 15.


15.Turn the ignition switch OFF.

16.Check for continuity between DLC terminal No. 7 and body ground.

 

Is there 5 W or less?


YES - Go to 17.


NO - Go to 18.

17.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
  • ECM connector No. 2 (58P)

Does continuity go away when one of the above components is disconnected?


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


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-keyless control unit, the audio unit, the under-dash fuse/relay box, or the ECM.n

18.Connect DLC terminal No. 7 to body ground with a jumper wire.

 

19.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-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 unit which cannot communicate with HDS.n


NO - Repair open in the wire between the DLC (K-line) and the appropriate connector.n

20.Do the gauge self- diagnostic function.

21.Check for B-CAN system DTCs without the HDS.

Is DTC B1168, B1169 and/or B1178 indicated?


YES - Go to 30.


NO - Go to 22.


22.Turn the ignition switch OFF.

23.Disconnect the HDS from the DLC.

24.Measure voltage between DLC terminal No. 16 and body ground.

 

Is there battery voltage?


YES - Go to 25.


NO - Repair open in the wire between DLC terminal No. 16 and the No. 16 BACK UP (10 A) fuse in the under-hood fuse/relay box.n

25.Measure voltage between DLC terminals No. 4 and No. 16.

 

Is there battery voltage?


YES - Go to 26.


NO - Repair open in the wire between DLC terminal No. 4 and body ground (G502).n


26.Turn the ignition switch OFF, and wait 1 minute.

27.Disconnect ECM connector No. 2 (58P).

28.Check for continuity between ECM connector No. 2 terminal No. 47 and DLC terminal No. 6.

 

Is there continuity?


YES - Go to 29.


NO - Repair open in the wire between DLC terminal No. 6 and ECM connector No. 2 terminal No. 47.n

29.Check for continuity between ECM connector No. 2 terminal No. 48 and DLC terminal No. 14.

 

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.n


NO - Repair open in the wire between DLC terminal No. 14 and ECM connector No. 2 terminal No. 48.n

30.Try to start the engine.

Does the engine start and idle smoothly?


YES - Go to F-CAN circuit troubleshooting.n


NO - Go to 31.


31.Press the inertia switch button.

32.Try to start the engine.

Does the engine start?


YES - Troubleshooting is complete.n


NO - Go to 33.


33.Turn the ignition switch OFF.

34.Inspect the No. 9 IGP (20 A) fuse in the under-hood fuse/relay box.

Is the fuse OK?


YES - Go to 39.


NO - Go to 35.

35.Disconnect the under-hood fuse/relay box 20P (white) connector.

36.Disconnect the fuel rail pressure control valve 2P connector.

37.Disconnect ECM connector No. 2 (58P).

38.Check for continuity between ECM connector No. 2 terminal No. 1 and body ground.

 

Is there continuity?


YES - Repair short in the wire between the under-hood fuse/relay box, the fuel rail pressure control valve, and the ECM connector No. 2 terminal No. 1, No. 3 or No. 5. Also replace the No. 9 IGP (20 A) fuse.n


NO -

39.Turn the ignition switch OFF, and wait 1 minute.

40.Disconnect ECM connector No. 2 (58P).

41.Measure voltage between ECM connector No. 2 terminal No. 19 and body ground.

 

Is there battery voltage?


YES - Go to 42.


NO - Go to 51.


42.Turn the ignition switch ON (II).

43.Measure voltage between ECM connector No. 2 terminal No. 35 and body ground.

 

Is there battery voltage?


YES - Go to 45.


NO - Go to 44.

44.Inspect the No. 2 FUEL PUMP (15 A) fuse in the under-dash fuse/relay box.

Is the fuse OK?


YES - Repair open in the wire between the No. 2 FUEL PUMP (15 A) fuse and ECM connector No. 2 terminal No. 35.n


NO - Repair short in the wire between the No. 2 FUEL PUMP (15 A) fuse and ECM connector No. 2 terminal No. 35.n


45.Turn the ignition switch OFF.

46.Remove the under-hood fuse/relay box.

47.Test PGM-FI main relay 1.

Is PGM-FI main relay 1 OK?


YES - Go to 48.


NO - Replace the under-hood fuse/relay box.n

48.Connect under-hood fuse/relay box 20P (white) connector terminal No. 17 to body ground with a jumper wire.

 

49.Check for continuity between body ground and ECM connector No. 2 terminals No. 1, No. 3, and No. 5 individually.

 

Is there continuity?


YES - Go to 50.


NO - Repair open in the wire between the under-hood fuse/relay box and the ECM connector No. 2 terminal No. 1, No. 3 or No. 5.n

50.Check for continuity between body ground and ECM connector No. 2 terminals No. 2, No. 4, and No. 6 individually.

 

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.n


NO - Repair open in the wire between the ECM connector No. 2 terminal No. 2, No. 4, or No. 6 and body ground (G502).n


51.Remove the under-hood fuse/relay box.

52.Test PGM-FI main relay 1.

Is PGM-FI main relay 1 OK?


YES - Go to 53.


NO - Replace the under-hood fuse/relay box.n

53.Connect under-hood fuse/relay box 20P (white) connector terminal No. 20 to body ground with a jumper wire.

 

54.Check for continuity between ECM connector No. 2 terminal No. 19 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.n


NO - Go to 55.

55.Disconnect the inertia switch 3P connector.

56.Connect the inertia switch 3P connector terminals No. 1 and No. 3 with a jumper wire.

 

57.Check for continuity between ECM connector No. 2 terminal No. 19 and body ground.

 

Is there continuity?


YES - Replace the inertia switch.n


NO - Repair open in the wire between the under-hood fuse/relay box and the ECM connector No. 2 terminal No. 19.n