DTC P1602 [L3]

BME010201600211

DTC P1602

Immobilizer unit-PCM communication error

DETECTION CONDITION

• Command transmission from the PCM to the immobilizer control module exceeds limit.
• No response from immobilizer control module.

POSSIBLE CAUSE

• Immobilizer unit malfunction
• Coil (immobilizer system) malfunction
• Key (transponder) malfunction
• PCM malfunction
• Open circuit in wiring between immobilizer control module terminal A and PCM terminal 2Q
• Open circuit in wiring between immobilizer control module terminal C and body ground
• Open circuit in wiring between immobilizer control module terminal F and coil terminal A
• Open circuit in wiring between immobilizer control module terminal D and coil terminal C
• Short to ground circuit in wiring between immobilizer control module terminal A and PCM terminal 2Q
• Short to ground circuit in wiring between immobilizer control module terminal F and coil terminal A
• Short to ground circuit in wiring between immobilizer control module terminal D and coil terminal C
• Poor connection of immobilizer control module, PCM connector or coil
• Open circuit in wiring between immobilizer control module terminal J and battery positive terminal

Diagnostic procedure

STEP

INSPECTION

ACTION

1
PERFORM DTC CONFIRMATION PROCEDURE
• Perform DTC CONFIRMATION PROCEDURE.
• Is same DTC present?
Yes
Go to the next step.
No
Intermittent concern exists. Go to INTERMITTENT CONCERN TROUBLESHOOTING procedure.
2
CLASSIFY NO DTC DETECTED OR SOME DTC DETECTED
• Clear the DTC from the PCM memory using the WDS or equivalent.
• Turn the ignition switch off and to the ON position (Engine off).
• Has DTC P1624 been detected?
Yes
Go to step 10.
No
Go to the next step.
3
INSPECT POOR CONNECTION OF IMMOBILIZER CONTROL MODULE CONNECTOR
• Turn the ignition switch off.
• Disconnect immobilizer control module connector.
• Inspect for poor connection (damaged, pulled-out terminals, corrosion, etc.).
• Is there any malfunction?
Yes
Repair or replace the terminals, then go to Step 19.
No
Go to the next step.
4
INSPECT GROUND CIRCUIT OF IMMOBILIZER CONTROL MODULE FOR OPEN CIRCUIT
• Measure the resistance between immobilizer control module terminal C (wiring harness-side) and body ground.
• Is there continuity?
Yes
Go to the next step.
No
Repair or replace the wiring harness for open circuit, then go to Step 19.
5
INSPECT COIL TERMINAL
• Disconnect the coil connector.
• Inspect for bent terminals.
• Is there any malfunction?
Yes
Repair or replace the terminals, then go to Step 19.
No
Go to the next step.
6
INSPECT COIL FOR SHORT CIRCUIT
• Inspect for continuity between coil terminal A (part-side) and body ground.
• Is there continuity?
Yes
Replace the coil, then go to Step 19.
No
Go to the next step.
7
INSPECT COIL CIRCUIT FOR SHORT
• Connect coil connector.
• Inspect for continuity between immobilizer control module terminal F (wiring harness-side) and body ground.
• Is there continuity?
Yes
Repair or replace the wiring harness for short circuit, then go to Step 19.
No
Go to the next step.
8
INSPECT POOR CONNECTION OF PCM CONNECTOR
• Disconnect the PCM connector.
• Inspect for poor connection (such as damaged, pulled-out terminals, corrosion).
• Is there any malfunction?
Yes
Repair or replace the wiring harness, then go to Step 19.
No
Go to the next step.
9
INSPECT COMMUNICATION LINE FOR OPEN
• Inspect for continuity between immobilizer control module terminal A (wiring harness-side) and PCM terminal 2Q.
• Is there continuity?
Yes
Go to step 19.
No
Repair or replace the wiring harness for open circuit, then go to Step 19.
10
CLASSIFY MALFUNCTION BY ANOTHER DETECTED DTCS
• Has DTC P1602 detected?
Yes
Go to Step 14.
No
Go to the next step.
11
INSPECT POOR CONNECTION OF COIL CONNECTOR
• Disconnect the coil connector.
• Inspect for poor connection (such as damaged/pulled-out terminals, corrosion).
• Is there any malfunction?
Yes
Repair or replace the wiring harness, then go to Step 19.
No
Go to the next step.
12
INSPECT COIL FOR OPEN CIRCUIT
• Disconnect coil connector.
• Measure the resistance between coil terminals (part-side).
• Is there continuity?
Yes
Go to the next step.
No
Replace the coil, then go to Step 19.
13
INSPECT COIL CIRCUIT FOR OPEN CIRCUIT
• Connect the coil connector.
• Measure the resistance between immobilizer connector F and D (wiring harness-side).
• Is there continuity?
Yes
Go to Step 19.
No
Repair or replace the wiring harness for open circuit, then go to Step 19.
14
CLASSIFY MALFUNCTION BY ANOTHER DETECTED DTCS.
• Has immobilizer control module DTC 03 been detected?
Yes
Key has not transponder, change to registered key.
Then go to Step 19.
No
Go to the next step.
15
CLASSIFY MALFUNCTION BY ANOTHER DETECTED DTCS.
• Has immobilizer control module DTC 01 detected?
Yes
Key that using for ignition is not registered.
Reprogram key or using another registered key, then go to the next step.
No
Go to the next step.
16
INSPECT POOR CONNECTION OF IMMOBILIZER CONTROL MODULE CONNECTOR
• Turn the ignition switch off.
• Disconnect immobilizer control module connector.
• Inspect for poor connection (such as damaged/pulled-out terminals, corrosion).
• Is there any malfunction?
Yes
Repair or replace the wiring harness, then go to the next step.
No
Go to the next step.
17
INSPECT IMMOBILIZER CONTROL MODULE POWER CIRCUIT FOR OPEN CIRCUIT
• Turn the ignition switch to the ON position (Engine off).
• Measure the voltage between immobilizer connector J (wiring harness-side) and body ground.
• Is the voltage B+?
Yes
Go to the next step.
No
Repair or replace the wiring harness for open circuit, then go to Step 19.
18
INSPECT COMMUNICATION LINE FOR SHORT HARNESS
• Measure the resistance between immobilizer control module terminal A (wiring harness-side) and body ground.
• Is there continuity?
Yes
Repair or replace the wiring harness for short, then go to the next step.
No
Go to the next step.
19
VERIFY TROUBLESHOOTING OF DTC P1602 COMPLETED
• Make sure to reconnect all disconnected connectors.
• Clear the DTC from the PCM memory using the WDS or equivalent.
• Perform KOEO self-test.
• Is the same DTC present?
Yes
Replace the PCM, then go to the next step.
No
Go to the next step.
20
VERIFY AFTER REPAIR PROCEDURE
• Perform "After Repair Procedure".
• Is there any DTC present?
Yes
Go to the applicable DTC inspection.
No
Troubleshooting completed.