DLC Circuit Troubleshooting
DLC Circuit Troubleshooting
NOTE: If you suspect the HDS or the HDS DLC cable may be the source of the communication problem, verify that they are working properly by connecting them to a known-good, similar vehicle and system, and checking for communication problems.

1.
HDS communication check:

HDS communication check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Connect the HDS to the DLC.
NOTE: Make sure the HDS is properly connected to the DLC.

?3.
Turn the vehicle to the ON mode, and turn on the HDS.

Does the HDS identify the vehicle?

     
YES
     
     
     
Go to step 2.
     
NO
     
     
     
Go to step 11.
2.
Determine possible failure area (PGM-FI system, other systems):

Determine possible failure area (PGM-FI system, other systems)
?1.
Check for Pending or Confirmed DTCs in the PGM-FI system with the HDS.
DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
       

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, go to step 3.
     
NO
     
     
     
If the HDS does not communicate with the EPS system, go to step 4.
     
NO
     
     
     
If the HDS does not communicate with the IMMOBI (immobilizer) system, go to step 5.
     
NO
     
     
     
If the HDS does not communicate with the ONE PUSH START system, go to step 6.
     
NO
     
     
     
If the HDS does not communicate with the BODY ELECTRICAL system, go to step 7.
3.
SRS check:

SRS check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Turn the vehicle to the ON mode, and watch the SRS indicator.

Does the SRS indicator come on and go off?

     
YES
     
     
     
The SRS is OK. Go to step 8.
     
NO
     
     
     
4.
EPS system check:

EPS system check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Start the engine, and watch the EPS indicator.

Does the EPS indicator come on and go off?

     
YES
     
     
     
The EPS system is OK. Go to step 8.
     
NO
     
     
     
5.
Immobilizer system check:

Immobilizer system check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Turn the vehicle to the ON mode, and watch the immobilizer indicator.

Does the immobilizer indicator stay on or flash?

     
YES
     
     
     
     
NO
     
     
     
The immobilizer system is OK. Go to step 8.
6.
Keyless access system check:

Keyless access system check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Turn the vehicle to the ON mode, and watch the keyless access indicator and the immobilizer indicator.

Does the keyless access indicator stay on or the immobilizer indicator stay on or flash?

     
YES
     
     
     
     
NO
     
     
     
The keyless access system is OK. Go to step 8.
7.
Body electrical system check:

Body electrical system check
?1.
Do the gauge self-diagnostic function.

?2.
Check the gauge display.

Is Error 2 indicated?

     
YES
     
     
     
Go to the indicated DTC's troubleshooting.?
     
NO
     
     
     
The body electrical system is OK. Go to step 8.
8.
Open wire check (K LINE line or L-LINE line):

Open wire check (K LINE line or L-LINE line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the HDS from the DLC.

?3.
Disconnect the control unit(s) on the K LINE or L-LINE that does not communicate.
K LINE
SRS unit connector A (39P)
EPS control unit connector A (11P)
Audio-navigation unit connector A (24P) (with navigation)
Audio unit connector A (24P) (without navigation)
Under-dash fuse/relay box connector Q (16P)
Immobilizer-keyless control unit 7P connector (without keyless access system)
Keyless access control unit connector B (28P) (with keyless access system)
Front passenger's weight sensor unit A (6P) (USA and Canada models)

L-LINE
Keyless access control unit connector C (24P) (with keyless access system)

?4.
Check for continuity between DLC (16P) No. 7 (K LINE line) and these connector terminals, or DLC (16P) No. 15 (L-LINE line) and these connector terminals:
K LINE
Connector
Terminal
SRS unit connector A (39P)
No. 19
EPS control unit connector A (11P)
No. 5
Audio-navigation unit connector A (24P)
No. 13
Audio unit connector A (24P)
No. 13
Under-dash fuse/relay box connector Q (16P)
No. 14
Immobilizer-keyless control unit 7P connector
No. 3
Keyless access control unit connector B (28P)
No. 20
Front passenger's weight sensor unit A (6P)
(USA and Canada models)
No. 2

L-LINE
Connector
Terminal
Keyless access control unit connector C (24P)
No. 3

Is there continuity between the DLC and the terminals in the chart?

     
YES
     
     
     
Go to step 9.
     
NO
     
     
     
Repair an open in the wire between the DLC (K LINE wire or L-LINE wire) and the appropriate connector.?
9.
Determine possible failure area (short in K LINE line or L-LINE line, others):

Determine possible failure area (short in K LINE line or L-LINE line, others)
?1.
Reconnect all connectors.

?2.
Turn the vehicle to the ON mode.

?3.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
Test point 1
DLC (16P) No. 7 and No. 15
Test point 2
Body ground


Is there any voltage?

     
YES
     
     
     
Go to step 11.
     
NO
     
     
     
Go to step 10.
10.
Shorted wire check (K LINE line, L-LINE line):

Shorted wire check (K LINE line, L-LINE line)
?1.
Continue to measure the voltage between DLC (16P) No. 7 (K LINE line) and body ground, or DLC (16P) No. 15 (L-LINE line) and body ground while disconnecting these parts, one at a time:
NOTE: Turn the vehicle to the OFF (LOCK) mode before disconnecting the connector, and turn the vehicle to the ON mode before measuring the voltage.

K LINE
SRS unit connector A (39P)
EPS control unit connector A (11P)
Audio-navigation unit connector A (24P) (with navigation)
Audio unit connector A (24P) (without navigation)
Under-dash fuse/relay box connector Q (16P)
Immobilizer-keyless control unit 7P connector (without keyless access system)
Keyless access control unit connector B (28P) (with keyless access system)
Front passenger's weight sensor unit A (6P) (USA and Canada models)

L-LINE
Keyless access control unit connector C (24P) (with keyless access system)

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

     
YES
     
     
     
Replace the part that any voltage was detected when it was disconnected.?
     
NO
     
     
     
Repair a short in the wire between DLC (16P) No. 7 (K LINE) and the SRS unit, the EPS control unit, the audio-navigation unit, the audio unit, under-dash fuse/relay box (MICU), the immobilizer-keyless control unit, the keyless access control unit, the front passenger's weight sensor unit (USA and Canada models), or DLC (16P) No. 15 (L-LINE line) and the keyless access control unit.?
11.
Body electrical system (B-CAN) check:

Body electrical system (B-CAN) check
?1.
Do the gauge self-diagnostic function.

?2.
Check for gauge control module DTCs without the HDS.

Is DTC U0029 and/or U0100 indicated?

     
YES
     
     
     
     
NO
     
     
     
Go to step 12.
12.
Open wire check (+B BACK UP line):

Open wire check (+B BACK UP line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the HDS from the DLC.

?3.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Test point 1
DLC (16P) No. 16
Test point 2
Body ground


Is there battery voltage?

     
YES
     
     
     
The +B BACK UP wire is OK. Go to step 13.
     
NO
     
     
     
Repair an open in the +B BACK UP wire between DLC (16P) No. 16 and the No. A29 (10 A) fuse in the under-hood fuse/relay box.?
13.
Open wire check (GND line):

Open wire check (GND line)
?1.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Test point 1
DLC (16P) No. 4
Test point 2
DLC (16P) No. 16


Is there battery voltage?

     
YES
     
     
     
The GND wire is OK. Go to step 14.
     
NO
     
     
     
Repair an open in the GND wire between DLC (16P) No. 4 and G502.?
14.
Open wire check (F-CAN_H line):

Open wire check (F-CAN_H line)
?1.
Jump the SCS line with the HDS, and wait more than 1 minute.


?2.
Disconnect the following connector.
PCM connector A (51P)

?3.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
PCM connector A (51P): disconnected
Test point 1
PCM connector A (51P) No. 2
Test point 2
DLC (16P) No. 6


Is there continuity?

     
YES
     
     
     
The F-CAN_H wire is not open. Go to step 15.
     
NO
     
     
     
Repair an open in the F-CAN_H wire between the PCM (A2) and DLC (16P) No. 6.?
15.
Open wire check (F-CAN_L line):

Open wire check (F-CAN_L line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
PCM connector A (51P): disconnected
Test point 1
PCM connector A (51P) No. 1
Test point 2
DLC (16P) No. 14


Is there continuity?

     
YES
     
     
     
The F-CAN_L wire is not open. Update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If the HDS identifies the vehicle and the PCM was updated, troubleshooting is complete. If the HDS identifies the vehicle and the PCM was substituted, replace the original PCM.?
     
NO
     
     
     
Repair an open in the F-CAN_L wire between the PCM (A1) and DLC (16P) No. 14.?