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)

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.
1		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
2		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
3		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].)
4		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].)
5		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].)
6		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.
7		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.)
8		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)

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.
1		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
2		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
3		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].)
4		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.
5		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.)
6		No	DTC troubleshooting completed.