DTC U0028:81/U0028:83/U0028:87 [BCM]

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Malfunction Location

Vehicles with advanced keyless and start system

•  DTC U0028:81 keyless control module communication error

•  DTC U0028:83 error signal from keyless control module

•  DTC U0028:87 no response from keyless control module

Vehicles with keyless entry system

•  DTC U0028:81 keyless receiver communication error

•  DTC U0028:83 error signal from keyless receiver

•  DTC U0028:87 no response from keyless receiver

Detection Condition

Vehicles with advanced keyless and start system

•  Communication error between keyless control module and BCM

Vehicles with keyless entry system

•  Communication error between keyless receiver and BCM

Possible Causes

Vehicles with advanced keyless and start system

•  Connection malfunction with connector

•  Open circuit in wiring harness between keyless control module terminal 2F and BCM terminal 6W

•  Short to ground circuit in wiring harness between keyless control module terminal 2F and BCM terminal 6W

•  Short to power supply in wiring harness between keyless control module terminal 2F and BCM terminal 6W

•  Keyless control module malfunction

•  BCM malfunction

Vehicles with keyless entry system

•  Connection malfunction with connector

•  Open circuit in wiring harness between keyless receiver (4-pin connector type) terminal C and BCM terminal 6W

•  Open circuit in wiring harness between keyless receiver (6-pin connector type) terminal D and BCM terminal 6W

•  Short to ground circuit in wiring harness between keyless receiver (4-pin connector type) terminal C and BCM terminal 6W

•  Short to ground circuit in wiring harness between keyless receiver (6-pin connector type) terminal D and BCM terminal 6W

•  Short to power supply between keyless receiver (4-pin connector type) terminal C and BCM terminal 6W

•  Short to power supply between keyless receiver (6-pin connector type) terminal D and BCM terminal 6W

•  Keyless receiver malfunction

•  BCM malfunction

System Wiring Diagram

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Diagnostic Procedure

Vehicles with advanced keyless and start system

Step	Inspection		Action
1	PERFORM DTC INSPECTION •  Clear DTCs using the M-MDS. (See CLEARING DTC [BCM].) •  Lock and unlock the doors using the transmitter. •  Perform the BCM DTC inspection using the M-MDS. (See DTC INSPECTION [BCM].) •  Are DTCs U0028:81, U0028:83, U0028:87 displayed?	Yes	Go to the next step.
		No	DTC troubleshooting completed.
2	VERIFY KEYLESS CONTROL MODULE CONNECTOR CONDITION •  Disconnect the negative and positive battery cables. •  Disconnect the keyless control module connector. •  Inspect the connection condition and wiring harness. •  Are the connector terminals normal without damage, deformation, corrosion, or disconnection?	Yes	Go to the next step.
		No	Repair or replace the connector, then go to the final step.
3	VERIFY KEYLESS CONTROL MODULE CONNECTOR CONDITION •  Remove the keyless control module. (See KEYLESS CONTROL MODULE REMOVAL/INSTALLATION [ADVANCED KEYLESS AND START SYSTEM].) •  Inspect the keyless control module. (See KEYLESS CONTROL MODULE INSPECTION [ADVANCED KEYLESS AND START SYSTEM].) •  Is the keyless control module normal?	Yes	Go to the next step.
		No	Replace the keyless control module, then go to the final step. (See KEYLESS CONTROL MODULE REMOVAL/INSTALLATION [ADVANCED KEYLESS AND START SYSTEM].)
4	VERIFY BCM CONNECTOR CONDITION •  Disconnect the BCM connector. •  Inspect the connection condition and wiring harness. •  Are the connector terminals normal without damage, deformation, corrosion, or disconnection?	Yes	Go to the next step.
		No	Repair or replace the connector, then go to the final step.
5	VERIFY WIRING HARNESS BETWEEN KEYLESS CONTROL MODULE AND BCM FOR SHORT TO GROUND •  Inspect for continuity between BCM terminal 6W and body ground. •  Is there continuity?	Yes	Repair or replace the related wiring harness, then go to the final step.
		No	Go to the next step.
6	VERIFY WIRING HARNESS BETWEEN KEYLESS CONTROL MODULE AND BCM FOR OPEN CIRCUIT •  Inspect for continuity between keyless control module terminal 2F and BCM terminal 6W. •  Is there continuity?	Yes	Go to the next step.
		No	Repair or replace the related wiring harness, then go to the final step.
7	VERIFY WIRING HARNESS BETWEEN KEYLESS CONTROL MODULE AND BCM FOR SHORT TO POWER SUPPLY •  Measure the voltage between BCM terminal 6W and body ground. •  Is there B+?	Yes	Repair or replace the related wiring harness, then go to the final step.
		No	Go to the next step.
8	VERIFY TROUBLESHOOTING COMPLETED •  Connect all the connectors. •  Connect the battery cable. •  Clear DTCs using the M-MDS. (See CLEARING DTC [BCM].) •  Lock and unlock the doors using the transmitter. •  Perform the BCM DTC inspection using the M-MDS. (See DTC INSPECTION [BCM].) •  Are DTCs U0028:81, U0028:83, U0028:87 displayed?	Yes	Replace the BCM. (See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION.)
		No	DTC troubleshooting completed.

Vehicles with Keyless Entry System

Step	Inspection		Action
1	PERFORM DTC INSPECTION •  Clear DTCs using the M-MDS. (See CLEARING DTC [BCM].) •  Lock and unlock the doors using the transmitter. •  Perform the BCM DTC inspection using the M-MDS. (See DTC INSPECTION [BCM].) •  Are DTCs U0028:81, U0028:83, U0028:87 displayed?	Yes	Go to the next step.
		No	DTC troubleshooting completed.
2	VERIFY KEYLESS RECEIVER CONNECTOR CONDITION •  Disconnect the negative and positive battery cables. •  Disconnect the keyless receiver connector (RH). •  Inspect the connection condition and wiring harness. •  Are the connector terminals normal without damage, deformation, corrosion, or disconnection?	Yes	Go to the next step.
		No	Repair or replace the connector, then go to the final step.
3	VERIFY KEYLESS RECEIVER CONDITION •  Remove the keyless receiver. (See KEYLESS RECEIVER REMOVAL/INSTALLATION [KEYLESS ENTRY SYSTEM].) •  Inspect the keyless receiver. (See KEYLESS RECEIVER INSPECTION [KEYLESS ENTRY SYSTEM].) •  Is the keyless receiver normal?	Yes	Go to the next step.
		No	Replace the keyless receiver, then go to the final step. (See KEYLESS RECEIVER REMOVAL/INSTALLATION [KEYLESS ENTRY SYSTEM].)
4	VERIFY BCM CONNECTOR CONDITION •  Disconnect the BCM connector. •  Inspect the connection condition and wiring harness. •  Are the connector terminals normal without damage, deformation, corrosion, or disconnection?	Yes	Go to the next step.
		No	Repair or replace the connector, then go to the final step.
5	VERIFY WIRING HARNESS BETWEEN KEYLESS RECEIVER AND BCM FOR SHORT TO GROUND •  Inspect for continuity between BCM terminal 6W and body ground. •  Is there continuity?	Yes	Repair or replace the related wiring harness, then go to the final step.
		No	Go to the next step.
6	VERIFY BETWEEN KEYLESS RECEIVER AND BCM FOR OPEN CIRCUIT •  Inspect for continuity between keyless receiver (4-pin connector type) terminal C/keyless receiver (6-pin connector type) terminal D and BCM terminal 6W. •  Is there continuity?	Yes	Go to the next step.
		No	Repair or replace the related wiring harness, then go to the final step.
7	VERIFY WIRING HARNESS BETWEEN KEYLESS RECEIVER AND BCM FOR SHORT TO POWER SUPPLY •  Measure the voltage between BCM terminal 6W and body ground. •  Is there B+?	Yes	Repair or replace the related wiring harness, then go to the final step.
		No	Go to the next step.
8	VERIFY TROUBLESHOOTING COMPLETED •  Connect all the connectors. •  Connect the battery cable. •  Clear DTCs using the M-MDS. (See CLEARING DTC [BCM].) •  Lock and unlock the doors using the transmitter. •  Perform the BCM DTC inspection using the M-MDS. (See DTC INSPECTION [BCM].) •  Are DTCs U0028:81, U0028:83, U0028:87 displayed?	Yes	Replace the BCM. (See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION.)
		No	DTC troubleshooting completed.