DTC U0127

id020200800600

With Advanced Keyless Entry And Start System

DTC U0127 | • Communication failure between instrument cluster and keyless CM
--- | ---
DETECTION CONDITION | • The instrument cluster cannot receive signal from the keyless CM.
POSSIBLE CAUSE | • Open or short circuit in the wiring harness between the keyless CM terminal 3Q and the instrument cluster terminal 1N. • Open or short circuit in the wiring harness between the keyless CM terminal 3Q and the BCM terminal 3B. • Open or short circuit in the wiring harness between the keyless CM terminal 3Q and the theft-deterrent CM terminal Q. • Keyless CM malfunction. • BCM malfunction • Theft-deterrent CM malfunction • Instrument cluster malfunction. • Poor connection at connectors (female terminal)

Diagnostic procedure

STEP | INSPECTION | ACTION
--- | --- | ---
1 | INSPECT WHEEL UNIT SIGNAL FOR OPEN CIRCUIT • Turn the ignition switch off. • Disconnect keyless CM, instrument cluster, BCM and theft-deterrent CM connectors. • Inspect for continuity between keyless CM terminal 3Q (harness-side) and instrument cluster terminal 1N (harness-side). • Inspect for continuity between keyless CM terminal 3Q (harness-side) and BCM terminal 3B (harness-side). • Inspect for continuity between keyless CM terminal 3Q (harness-side) and theft-deterrent CM terminal Q (harness-side). • Is there continuity? | Yes | Go to the next step.
No | Repair or replace the following wiring harness for an open circuit, then go to Step 7. ― Between keyless CM terminal 3Q and instrument cluster terminal 1N ― Between keyless CM terminal 3Q and BCM terminal 3B ― Between keyless CM terminal 3Q and theft-deterrent CM terminal Q
2 | INSPECT WHEEL UNIT SIGNAL FOR SHORT TO POWER • Turn the ignition switch off. • Disconnect keyless CM, instrument cluster, BCM and theft-deterrent CM connectors. • Measure the voltage between keyless CM terminal 3Q (harness-side) and ground. • Is there B+? | Yes | Repair or replace the following wiring harness for a short to power, then go to Step 7. ― Between keyless CM terminal 3Q and instrument cluster terminal 1N ― Between keyless CM terminal 3Q and BCM terminal 3B ― Between keyless CM terminal 3Q and theft-deterrent CM terminal Q
No | Go to the next step.
3 | INSPECT WHEEL UNIT SIGNAL FOR SHORT TO GROUND • Turn the ignition switch off. • Disconnect keyless CM, instrument cluster, BCM and theft-deterrent CM connectors. • Inspect for continuity between keyless CM terminal 3Q (harness-side) and ground. • Is there continuity? | Yes | Repair or replace the following wiring harness for a short to ground, then go to Step 7. ― Between keyless CM terminal 3Q and instrument cluster terminal 1N ― Between keyless CM terminal 3Q and BCM terminal 3B ― Between keyless CM terminal 3Q and theft-deterrent CM terminal Q
No | Go to the next step.
4 | INSPECT FOR KEYLESS CM MALFUNCTION • Turn the ignition switch off. • Using the M-MDS, perform the DTC inspection for the keyless CM. • Is any DTCs present? | Yes | Go to the applicable DTC inspection. (See DTC TABLE [IMMOBILIZER SYSTEM (ADVANCED KEYLESS ENTRY AND START SYSTEM)].) (See DTC TABLE [ADVANCED KEYLESS ENTRY AND START SYSTEM].)
No | Go to the next step.
5 | INSPECT FOR BCM MALFUNCTION • Turn the ignition switch off. • Using the M-MDS, perform the DTC inspection for the BCM. • Is any DTCs present? | Yes | Go to the applicable DTC inspection. (See DTC TABLE [BCM].)
No | Go to the next step.
6 | INSPECT FOR THEFT-DETERRENT CM MALFUNCTION • Turn the ignition switch off. • Using the M-MDS, perform the DTC inspection for the theft-deterrent CM. • Is any DTCs present? | Yes | Go to the applicable DTC inspection. (See DTC TABLE [THEFT-DETERRENT SYSTEM].)
No | Go to the next step.
7 | VERIFY TROUBLESHOOTING COMPLETED • Turn the ignition switch to the ON position and drive the vehicle at a speed of 25 km/h {15.5 mph} or more. • Clear the DTC from the memory. (See TIRE PRESSURE MONITORING SYSTEM (TPMS) ON-BOARD DIAGNOSIS.) • Is the same DTC present? | Yes | • If the malfunction recurs, replace the instrument cluster. (See INSTRUMENT CLUSTER REMOVAL/INSTALLATION.) • Configure the instrument cluster. (See INSTRUMENT CLUSTER CONFIGURATION.) • Register the wheel unit ID. (See WHEEL UNIT ID REGISTRATION.) • Go to the next step.
No | Go to the next step.
8 | VERIFY AFTER REPAIR PROCEDURE • Drive the vehicle at a speed of 25 km/h {15.5 mph} or more for 10 min or more. • Are there any other DTCs present? | Yes | Go to the applicable DTC inspection. (See TIRE PRESSURE MONITORING SYSTEM (TPMS) ON-BOARD DIAGNOSIS.)
No | DTC troubleshooting completed.

With Keyless Entry System

DTC U0127 | • Communication failure between instrument cluster and keyless receiver
--- | ---
DETECTION CONDITION | • The instrument cluster cannot receive signal from the keyless receiver.
POSSIBLE CAUSE | • Open or short circuit in the wiring harness between the keyless receiver terminal D and the instrument cluster terminal 1N. • Open or short circuit in the wiring harness between the keyless receiver terminal D and the BCM terminal 3B. • Keyless receiver malfunction. • BCM malfunction • Instrument cluster malfunction. • Poor connection at connectors (female terminal)

Diagnostic procedure

STEP | INSPECTION | ACTION
--- | --- | ---
1 | INSPECT WHEEL UNIT SIGNAL FOR OPEN CIRCUIT • Turn the ignition switch off. • Disconnect keyless receiver, instrument cluster and BCM connectors. • Inspect for continuity between keyless receiver terminal D (harness-side) and instrument cluster terminal 1N (harness-side). • Inspect for continuity between keyless receiver terminal D (harness-side) and BCM terminal 3B (harness-side). • Is there continuity? | Yes | Go to the next step.
No | Repair or replace the following wiring harness for an open circuit, then go to Step 5. ― Between keyless receiver terminal D and instrument cluster terminal 1N ― Between keyless receiver terminal D and BCM 3B
2 | INSPECT WHEEL UNIT SIGNAL FOR SHORT TO POWER • Turn the ignition switch off. • Disconnect keyless receiver, instrument cluster and BCM connectors. • Measure the voltage between keyless receiver terminal D (harness-side) and ground. • Is there B+? | Yes | Repair or replace the following wiring harness for a short to power, then go to Step 5. ― Between keyless receiver terminal D and instrument cluster terminal 1N ― Between keyless receiver terminal D and BCM 3B
No | Go to the next step.
3 | INSPECT WHEEL UNIT SIGNAL FOR SHORT TO GROUND • Turn the ignition switch off. • Disconnect keyless receiver, instrument cluster and BCM connectors. • Inspect for continuity between keyless receiver terminal D (harness-side) and ground. • Is there continuity? | Yes | Repair or replace the following wiring harness for a short to ground, then go to Step 5. ― Between keyless receiver terminal D and instrument cluster terminal 1N ― Between keyless receiver terminal D and BCM 3B
No | Replace keyless receiver, then go to the next step. (See KEYLESS RECEIVER REMOVAL/INSTALLATION.)
4 | INSPECT FOR BCM MALFUNCTION • Turn the ignition switch off. • Using the M-MDS, perform the DTC inspection for the BCM. • Is any DTCs present? | Yes | Go to the applicable DTC inspection. (See DTC TABLE [BCM].)
No | Go to the next step.
5 | VERIFY TROUBLESHOOTING COMPLETED • Clear the DTC from the memory. (See TIRE PRESSURE MONITORING SYSTEM (TPMS) ON-BOARD DIAGNOSIS.) • Turn the ignition switch to the ON position and wait for 30 s. • Is the same DTC present? | Yes | • If the malfunction recurs, replace the instrument cluster. (See INSTRUMENT CLUSTER REMOVAL/INSTALLATION.) • Configure the instrument cluster. (See INSTRUMENT CLUSTER CONFIGURATION.) • Register the wheel unit ID. (See WHEEL UNIT ID REGISTRATION.) • Go to the next step.
No | Go to the next step.
6 | VERIFY AFTER REPAIR PROCEDURE • Drive the vehicle at a speed of 25 km/h {15.5 mph} or more for 10 min or more. • Are there any other DTCs present? | Yes | Go to the applicable DTC inspection. (See TIRE PRESSURE MONITORING SYSTEM (TPMS) ON-BOARD DIAGNOSIS.)
No | DTC troubleshooting completed.