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DTC P1602 [L3]

BME010201600W01

DTC P1602 | Immobilizer unit-PCM communication error
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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 • PCM malfunction • Open circuit in wiring between immobilizer unit terminal A and PCM terminal 2Q
• Open circuit in wiring between immobilizer unit terminal C and body ground
• Open circuit in wiring between immobilizer unit terminal F and coil terminal A
• Open circuit in wiring between immobilizer unit terminal D and coil terminal C
• Short to ground circuit in wiring between immobilizer unit terminal A and PCM terminal 2Q
• Short to ground circuit in wiring between immobilizer unit terminal F and coil terminal A
• Short to ground circuit in wiring between immobilizer unit terminal D and coil terminal C
• Poor connection of immobilizer unit, PCM connector or coil
• Open circuit in wiring between immobilizer unit terminal J and battery positive terminal

Diagnostic procedure

STEP | INSPECTION | ACTION
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1 | PERFORM DTC CONFIRMATION PROCEDURE • Perform DTC CONFIRMATION PROCEDURE. (See DTC CONFIRMATION PROCEDURE [L3].) • Is same DTC present? | Yes | Go to next step.
No | Intermittent concern exists. Go to INTERMITTENT CONCERN TROUBLESHOOTING procedure. (See INTERMITTENT CONCERN TROUBLESHOOTING [L3].)
2 | CLASSIFY NO DTC DETECTED OR SOME DTC DETECTED • Clear DTC from memory using WDS or equivalent. • Turn ignition key to OFF and ON (Engine OFF). • Has DTC P1624 been detected? | Yes | Go to step 10.
No | Go to next step.
3 | INSPECT POOR CONNECTION OF IMMOBILIZER UNIT CONNECTOR • Turn ignition key to OFF. • Disconnect immobilizer unit connector. • Inspect for poor connection (damaged, pulled-out terminals, corrosion, etc.). • Is there any malfunction? | Yes | Repair or replace terminals, then go to Step 19.
No | Go to next step.
4 | INSPECT GROUND CIRCUIT OF IMMOBILIZER UNIT FOR OPEN CIRCUIT • Measure resistance between immobilizer unit terminal C (harness-side) and body ground. • Is there continuity? | Yes | Go to next step.
No | Repair or replace harness for open, then go to Step 19.
5 | INSPECT COIL TERMINAL • Disconnect coil connector. • Inspect for bent terminals. • Is there any malfunction? | Yes | Repair or replace terminals, then go to Step 19.
No | Go to next step.
6 | INSPECT COIL FOR SHORT CIRCUIT • Inspect continuity between coil terminal A (part-side) and body ground. • Is there continuity? | Yes | Replace coil, then go to Step 19.
No | Go to next step.
7 | INSPECT COIL CIRCUIT FOR SHORT • Connect coil connector. • Inspect continuity between immobilizer unit terminal F (harness-side) and body ground. • Is there continuity? | Yes | Repair or replace harness for short circuit, then go to Step 19.
No | Go to next step.
8 | INSPECT POOR CONNECTION OF PCM CONNECTOR • Disconnect PCM connector. • Inspect for poor connection (damaged, pulled-out terminals, corrosion, etc.). • Is there any malfunction? | Yes | Repair or replace harness, then go to Step 19.
No | Go to next step.
9 | INSPECT COMMUNICATION LINE FOR OPEN • Measure continuity between immobilizer unit terminal A (harness-side) and PCM terminal 2Q. • Is there continuity? | Yes | Go to step 19.
No | Repair or replace 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 next step.
11 | INSPECT POOR CONNECTION OF COIL CONNECTOR • Disconnect coil connector. • Inspect for poor connection (damaged, pulled-out terminals, corrosion, etc.). • Is there any malfunction? | Yes | Repair or replace harness, then go to Step 19.
No | Go to next step.
12 | INSPECT COIL FOR OPEN • Disconnect coil connector. • Measure resistance between coil terminals (part-side). • Is there continuity? | Yes | Go to next step.
No | Replace coil, then go to Step 19.
13 | INSPECT COIL CIRCUIT FOR OPEN CIRCUIT • Connect coil connector. • Measure the resistance between immobilizer connector F and D (harness-side). • Is there continuity? | Yes | Go to Step 19.
No | Repair or replace harness for open circuit, then go to Step 19.
14 | CLASSIFY MALFUNCTION BY ANOTHER DETECTED DTCS. • Has immobilizer unit DTC 03 been detected? | Yes | Key has not transponder, change to registered key. Then go to Step 19.
No | Go to next step.
15 | CLASSIFY MALFUNCTION BY ANOTHER DETECTED DTCS. • Has immobilizer unit DTC 01 detected? | Yes | Key that using for ignition is not registered. Reprogram key or using another registered key, then go to next step.
No | Go to next step.
16 | INSPECT POOR CONNECTION OF IMMOBILIZER UNIT CONNECTOR • Turn ignition key to OFF. • Disconnect immobilizer unit connector. • Inspect for poor connection (damaged, pulled-out terminals, corrosion, etc.). • Is there any malfunction? | Yes | Repair or replace harness, then go to next step.
No | Go to next step.
17 | INSPECT IMMOBILIZER UNIT POWER CIRCUIT FOR OPEN CIRCUIT • Turn ignition key to ON (Engine OFF). • Measure voltage between immobilizer connector J (harness-side) and body ground. • Is there voltage B+? | Yes | Go to next step.
No | Repair or replace harness for open circuit, then go to Step 19.
18 | INSPECT COMMUNICATION LINE FOR SHORT HARNESS • Measure resistance between immobilizer unit terminal A (harness-side) and body ground. • Is there continuity? | Yes | Repair or replace harness for short, then go to next step.
No | Go to next step.
19 | VERIFY TROUBLESHOOTING OF DTC P1602 COMPLETED • Make sure to reconnect all disconnected connectors. • Clear DTC from memory using WDS or equivalent. • Perform KOEO self-test. (See KOEO/KOER SELF-TEST PROCEDURE [L3].)
• Is same DTC present?
Yes
Replace PCM, then go to next step.
(See PCM REMOVAL/INSTALLATION [L3].)
No | Go to next step.
20 | VERIFY AFTER REPAIR PROCEDURE • Perform "After Repair Procedure". (See AFTER REPAIR PROCEDURE [L3].) • Is there any DTC present? | Yes | Go to applicable DTC troubleshooting. (See DTC TABLE [L3].)
No | Troubleshooting completed.