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

id0902f5341100

Vehicles With Advanced Keyless And Start System

Description

• DTC U0028:81: Communication error with keyless control module

• DTC U0028:83: Error signal from keyless control module

• DTC U0028:87: No response from keyless control module

Detection Condition

• Communication error between keyless control module and BCM.

Possible Causes

• Keyless control module connector or terminals malfunction

• BCM connector or terminals malfunction

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

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

• Keyless control module malfunction

• BCM malfunction

System Wiring Diagram

am2zzw00006129

Diagnostic Procedure

Step

Inspection

Action

1

VERIFY BCM DTCs

•  Clear the DTCs using the M-MDS.
(See CLEARING DTC [BCM].)

•  Perform the BCM DTC inspection using the M-MDS.
(See DTC INSPECTION [BCM].)

•  Is the same DTC present?

Yes

Go to the next step.

No

Go to Step 8.

2

INSPECT KEYLESS CONTROL MODULE CONNECTOR AND TERMINALS

•  Turn the ignition switch to the LOCK position.

•  Disconnect the negative battery cable.

•  Disconnect the keyless control module connector.

•  Inspect the connector and terminals (corrosion, damage, pin disconnection).

•  Is there any malfunction?

Yes

Repair or replace the connector or terminals, then go to Step 7.

No

Go to the next step.

3

INSPECT BCM CONNECTOR AND TERMINALS

•  Disconnect the BCM connector.

•  Inspect the connector and terminals (corrosion, damage, pin disconnection).

•  Is there any malfunction?

Yes

Repair or replace the connector or terminals, then go to Step 7.

No

Go to the next step.

4

INSPECT KEYLESS CONTROL MODULE CIRCUIT FOR SHORT TO GROUND

•  Verify that the keyless control module and BCM connectors are disconnected.

•  Inspect for continuity between keyless control module terminal 2F (wiring harness-side) and body ground.

•  Is there continuity?

Yes

Repair or replace the wiring harness for a possible short to ground, then go to Step 7.

No

Go to the next step.

5

INSPECT KEYLESS CONTROL MODULE CIRCUIT FOR OPEN CIRCUIT

•  Verify that the keyless control module and BCM connectors are disconnected.

•  Inspect for continuity between keyless control module terminal 2F (wiring harness-side) and BCM terminal 6W (wiring harness-side).

•  Is there continuity?

Yes

Go to the next step.

No

Repair or replace the wiring harness for a possible open circuit, then go to Step 7.

6

INSPECT KEYLESS CONTROL MODULE

•  Make sure to reconnect all disconnected connectors.

•  Reconnect the negative battery cable.

•  Measure the voltage at the keyless control module terminal 2F (wiring harness-side).

•  Is the voltage normal?
(See KEYLESS CONTROL MODULE INSPECTION [ADVANCED KEYLESS AND START SYSTEM].)

Yes

Go to the next step.

No

Replace the keyless control module, then go to the next step.

(See KEYLESS CONTROL MODULE REMOVAL/INSTALLATION [ADVANCED KEYLESS AND START SYSTEM].)

7

VERIFY TROUBLESHOOTING COMPLETED

•  Make sure to reconnect all disconnected connectors.

•  Reconnect the negative battery cable.

•  Clear the DTCs using the M-MDS.
(See CLEARING DTC [BCM].)

•  Perform the BCM DTC inspection using the M-MDS.
(See DTC INSPECTION [BCM].)

•  Is the same DTC present?

Yes

Repeat the inspection from Step 1.

•  If the malfunction recurs, replace the BCM.
(See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION.)

Go to the next step.

No

Go to the next step.

8

VERIFY THAT NO OTHER DTCs ARE PRESENT

•  Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [BCM].)

No

DTC troubleshooting completed.

Step	Inspection	Action
1	VERIFY BCM DTCs • Clear the DTCs using the M-MDS. (See CLEARING DTC [BCM].) • Perform the BCM DTC inspection using the M-MDS. (See DTC INSPECTION [BCM].) • Is the same DTC present?	Yes	Go to the next step.
No	Go to Step 8.
2	INSPECT KEYLESS CONTROL MODULE CONNECTOR AND TERMINALS • Turn the ignition switch to the LOCK position. • Disconnect the negative battery cable. • Disconnect the keyless control module connector. • Inspect the connector and terminals (corrosion, damage, pin disconnection). • Is there any malfunction?	Yes	Repair or replace the connector or terminals, then go to Step 7.
No	Go to the next step.
3	INSPECT BCM CONNECTOR AND TERMINALS • Disconnect the BCM connector. • Inspect the connector and terminals (corrosion, damage, pin disconnection). • Is there any malfunction?	Yes	Repair or replace the connector or terminals, then go to Step 7.
No	Go to the next step.
4	INSPECT KEYLESS CONTROL MODULE CIRCUIT FOR SHORT TO GROUND • Verify that the keyless control module and BCM connectors are disconnected. • Inspect for continuity between keyless control module terminal 2F (wiring harness-side) and body ground. • Is there continuity?	Yes	Repair or replace the wiring harness for a possible short to ground, then go to Step 7.
No	Go to the next step.
5	INSPECT KEYLESS CONTROL MODULE CIRCUIT FOR OPEN CIRCUIT • Verify that the keyless control module and BCM connectors are disconnected. • Inspect for continuity between keyless control module terminal 2F (wiring harness-side) and BCM terminal 6W (wiring harness-side). • Is there continuity?	Yes	Go to the next step.
No	Repair or replace the wiring harness for a possible open circuit, then go to Step 7.
6	INSPECT KEYLESS CONTROL MODULE • Make sure to reconnect all disconnected connectors. • Reconnect the negative battery cable. • Measure the voltage at the keyless control module terminal 2F (wiring harness-side). • Is the voltage normal? (See KEYLESS CONTROL MODULE INSPECTION [ADVANCED KEYLESS AND START SYSTEM].)	Yes	Go to the next step.
No	Replace the keyless control module, then go to the next step. (See KEYLESS CONTROL MODULE REMOVAL/INSTALLATION [ADVANCED KEYLESS AND START SYSTEM].)
7	VERIFY TROUBLESHOOTING COMPLETED • Make sure to reconnect all disconnected connectors. • Reconnect the negative battery cable. • Clear the DTCs using the M-MDS. (See CLEARING DTC [BCM].) • Perform the BCM DTC inspection using the M-MDS. (See DTC INSPECTION [BCM].) • Is the same DTC present?	Yes	Repeat the inspection from Step 1. • If the malfunction recurs, replace the BCM. (See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION.) Go to the next step.
No	Go to the next step.
8	VERIFY THAT NO OTHER DTCs ARE PRESENT • Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [BCM].)
No	DTC troubleshooting completed.

Vehicles With Keyless Entry System

Description

• DTC U0028:81: Communication error with keyless receiver

• DTC U0028:83: Error signal from keyless receiver

• DTC U0028:87: No response from keyless receiver

Detection Condition

• Communication error between keyless receiver and BCM.

Possible Causes

• Keyless receiver connector or terminals malfunction

• BCM connector or terminals malfunction

• Short to ground in wiring harness between keyless receiver terminal D and BCM terminal 6W

• Open circuit in wiring harness between keyless receiver terminal D and BCM terminal 6W

• Keyless receiver malfunction

• BCM malfunction

System Wiring Diagram

am2zzw00006130

Diagnostic Procedure

Step

Inspection

Action

1

VERIFY BCM DTCs

•  Clear the DTCs using the M-MDS.
(See CLEARING DTC [BCM].)

•  Perform the BCM DTC inspection using the M-MDS.
(See DTC INSPECTION [BCM].)

•  Is the same DTC present?

Yes

Go to the next step.

No

Go to Step 8.

2

INSPECT KEYLESS RECEIVER CONNECTOR AND TERMINALS

•  Turn the ignition switch to the LOCK position.

•  Disconnect the negative battery cable.

•  Disconnect the keyless receiver connector.

•  Inspect the connector and terminals (corrosion, damage, pin disconnection).

•  Is there any malfunction?

Yes

Repair or replace the connector or terminals, then go to Step 7.

No

Go to the next step.

3

INSPECT BCM CONNECTOR AND TERMINALS

•  Disconnect the BCM connector.

•  Inspect the connector and terminals (corrosion, damage, pin disconnection).

•  Is there any malfunction?

Yes

Repair or replace the connector or terminals, then go to Step 7.

No

Go to the next step.

4

INSPECT KEYLESS RECEIVER CIRCUIT FOR SHORT TO GROUND

•  Verify that the keyless receiver and BCM connectors are disconnected.

•  Inspect for continuity between keyless receiver terminal D (wiring harness-side) and body ground.

•  Is there continuity?

Yes

Repair or replace the wiring harness for a possible short to ground, then go to Step 7.

No

Go to the next step.

5

INSPECT KEYLESS RECEIVER CIRCUIT FOR OPEN CIRCUIT

•  Verify that the keyless receiver and BCM connectors are disconnected.

•  Inspect for continuity between keyless receiver terminal D (wiring harness-side) and BCM terminal 6W (wiring harness-side).

•  Is there continuity?

Yes

Go to the next step.

No

Repair or replace the wiring harness for a possible open circuit, then go to Step 7.

6

INSPECT KEYLESS RECEIVER

•  Inspect the keyless receiver.
(See KEYLESS RECEIVER INSPECTION [KEYLESS ENTRY SYSTEM].)

•  Is there any malfunction?

Yes

Replace the keyless receiver, then go to Step 7.

(See KEYLESS RECEIVER REMOVAL/INSTALLATION [KEYLESS ENTRY SYSTEM].)

No

Go to the next step.

7

VERIFY TROUBLESHOOTING COMPLETED

•  Make sure to reconnect all disconnected connectors.

•  Reconnect the negative battery cable.

•  Clear the DTCs using the M-MDS.
(See CLEARING DTC [BCM].)

•  Perform the BCM DTC inspection using the M-MDS.
(See DTC INSPECTION [BCM].)

•  Is the same DTC present?

Yes

Repeat the inspection from Step 1.

•  If the malfunction recurs, replace the BCM.
(See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION.)

Go to the next step.

No

Go to the next step.

8

VERIFY THAT NO OTHER DTCs ARE PRESENT

•  Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [BCM].)

No

DTC troubleshooting completed.