DTC P1602 [MZR-CD (RF Turbo)]


BME010200102287

DTC P1602

Immobilizer unit-PCM communication error

DETECTION CONDITION

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

POSSIBLE CAUSE

• Immobilizer unit malfunction
• Coil (immobilizer system) malfunction
• Key (transponder) malfunction
• Open circuit in wiring harness between immobilizer unit terminal A and PCM terminal 54
• Open circuit in wiring harness between immobilizer unit terminal C and body GND
• Open circuit in wiring harness between immobilizer unit terminal D and coil terminal C
• Open circuit in wiring harness between immobilizer unit terminal F and coil terminal A
• Short to GND in wiring harness between immobilizer unit terminal A and PCM terminal 54
• Short to GND in wiring harness between immobilizer unit terminal D and coil terminal C
• Short to GND in wiring harness between immobilizer unit terminal F and coil terminal A
• PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1
VERIFY RELATED REPAIR INFORMATION AVAILABILITY
• Check for related Service Information availability.
• Is any related repair information available?
Yes
Perform repair or diagnosis according to available Service Information.
• If the vehicle is not repaired, go to the next step.
No
Go to the next step.
2
VERIFY DTC P1602 DETECTED AGAIN
• Clear the DTC from the PCM memory using the WDS or equivalent.
• Start the engine.
• Is the same DTC present?
Yes
Go to Step 10.
No
Go to the next step.
3
INSPECT POOR CONNECTION OF IMMOBILIZER UNIT CONNECTOR
• Turn the engine switch off.
• Inspect for poor connection (such as damaged/pulled-out terminals, corrosion).
• Is there any malfunction?
Yes
Repair or replace the terminal, go to Step 19.
No
Go to the next step.
4
INSPECT IMMOBILIZER CONTROL UNIT GND CIRCUIT FOR OPEN
• Turn the engine switch off.
• Inspect for continuity between immobilizer unit terminal C and body GND.
• Is there continuity?
Yes
Go to the next step.
No
Repair or replace the wiring harness for an open circuit, go to Step 19.
5
INSPECT POOR CONNECTION OF COIL CONNECTOR
• Turn the engine switch off.
• Inspect for poor connection (such as damaged/pulled-out terminals, corrosion).
• Is there any malfunction?
Yes
Repair or replace the terminal, go to Step 19.
No
Go to the next step.
6
INSPECT COIL FOR SHORT TO GND
• Turn the engine switch off.
• Inspect for continuity between coil terminal A and body GND.
• Is there continuity?
Yes
Replace the coil, go to Step 19.
No
Go to the next step.
7
INSPECT COIL CIRCUIT FOR SHORT TO GND
• Turn the engine switch off.
• Inspect for continuity between immobilizer unit terminal F and body GND.
• Is there continuity?
Yes
Repair or replace the wiring harness for short to GND, go to Step 19.
No
Go to the next step.
8
INSPECT POOR CONNECTION OF PCM CONNECTOR
• Turn the engine switch off.
• Inspect for poor connection (such as damaged/pulled-out terminals, corrosion).
• Is there any malfunction?
Yes
Repair or replace the terminal, go to Step 19.
No
Go to the next step.
9
INSPECT IMMOBILIZER UNIT SIGNAL CIRCUIT FOR OPEN
• Turn the engine switch off.
• Inspect for continuity between immobilizer unit terminal A and PCM terminal 54.
• Is there continuity?
Yes
Go to step 19.
No
Repair or replace the wiring harness for an open circuit, go to Step 19.
10
CLASSIFY MALFUNCTION BY ANOTHER DETECTED DTCS
• Is DTC P1602 present?
Yes
Go to Step 14.
No
Go to the next step.
11
INSPECT POOR CONNECTION OF COIL CONNECTOR
• Turn the engine switch off.
• Inspect for poor connection (such as damaged/pulled-out terminals, corrosion).
• Is there any malfunction?
Yes
Repair or replace the terminal, go to Step 19.
No
Go to the next step.
12
INSPECT COIL FOR OPEN
• Turn the engine switch off.
• Inspect for continuity between coil terminals A and C.
• Is there continuity?
Yes
Go to the next step.
No
Replace the coil, go to Step 19.
13
INSPECT COIL CIRCUIT FOR OPEN
• Turn the engine switch off.
• Inspect for continuity between immobilizer unit terminals D and F.
• Is there continuity?
Yes
Go to Step 19.
No
Repair or replace the wiring harness for an open circuit, go to Step 19.
14
CLASSIFY MALFUNCTION BY OTHER DETECTED DTCS.
• Is immobilizer unit DTC 03 present?
Yes
Key does not have transponder, change to registered key.
Go to Step 19.
No
Go to the next step.
15
CLASSIFY MALFUNCTION BY OTHER DETECTED DTCS.
• Is immobilizer unit DTC 01 present?
Yes
Key is not registered.
Reprogram key or use another registered key, go to the next step.
No
Go to the next step.
16
INSPECT POOR CONNECTION OF IMMOBILIZER UNIT CONNECTOR
• Turn the engine switch off.
• Inspect for poor connection (such as damaged/pulled-out terminals, corrosion).
• Is there any malfunction?
Yes
Repair or replace the terminal, go to the next step.
No
Go to the next step.
17
INSPECT IMMOBILIZER UNIT POWER CIRCUIT FOR OPEN
• Turn the engine switch off.
• Inspect the voltage between immobilizer unit terminal J and body GND.
• Is the voltage B+?
Yes
Go to the next step.
No
Repair or replace the wiring harness for an open circuit, go to Step 19.
18
INSPECT IMMOBILIZER CONTROL UNIT SIGNAL CIRCUIT FOR SHORT TO GND
• Turn the engine switch off.
• Inspect for continuity between immobilizer unit terminal A and body GND.
• Is there continuity?
Yes
Repair or replace the wiring harness for short to GND, 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.
• Start the engine.
• Is the same DTC present?
Yes
Replace the PCM, 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.