Pinpoint Test E: DTC B126A: 01

Handles, Locks, Latches and Entry Systems

Pinpoint Tests

Pinpoint Test E: DTC B126A: 01

Refer to Wiring Diagram Set 110, Power Door Locks for schematic and connector information. Diagrams By Number

Normal Operation

The Body Control Module (BCM) sends voltage signals to the door lock control switches through the lock and unlock input circuits. When the lock or unlock switch is pressed, the corresponding voltage signal is routed to ground, signaling the BCM to lock or unlock the doors. The door lock control switches have a dedicated ground circuit.

- DTC B126A: 01 (Drivers Door Interior Lock Switch: General Electrical Failure) - sets when the BCM detects a short to ground from the lock or unlock request input circuits.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Door lock control switch
- BCM

PINPOINT TEST E: DTC B126A: 01

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

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E1 CHECK THE RECORDED BCM DTCs FROM THE SELF-TEST

- Check the recorded results from the BCM self-test.
- Is DTC B126A: 01 present?

Yes
GO to E2.

No
CHECK the symptom(s) and GO to Symptom Chart - Electrical. Symptom Related Diagnostic Procedures

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E2 CHECK THE LH DOOR LOCK CONTROL SWITCH

- Disconnect: LH Door Lock Control Switch C505 .
- Repeat the BCM self-test.
- Is DTC B126A: 01 retrieved again?

Yes
LEAVE the switch disconnected. GO to E3.

No
INSTALL a new LH door lock control switch. REFER to Door Lock Control Switch Service and Repair. TEST the system for normal operation.

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E3 CHECK THE RH DOOR LOCK CONTROL SWITCH

- Disconnect: RH Door Lock Control Switch C605 .
- Repeat the BCM self-test.
- Is DTC B126A: 01 retrieved again?

Yes
LEAVE the switch disconnected. GO to E4.

No
INSTALL a new RH door lock control switch. REFER to Door Lock Control Switch Service and Repair. TEST the system for normal operation.

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E4 CHECK THE LOCK OR UNLOCK INPUT CIRCUIT FOR A SHORT TO GROUND

- Ignition OFF.
- Disconnect: BCM C2280C .
- Measure the resistance between the RH Door Lock Control Switch C605-1, circuit CPK19 (BU/GN), harness side and ground; and between the RH Door Lock Control Switch C605-3, circuit CPK23 (YE/VT), harness side and ground.




- Are the resistances greater than 10,000 ohms?

Yes
GO to E5.

No
REPAIR circuit CPK19 (BU/GN) or circuit CPK23 (YE/VT) for a short to ground. CLEAR the DTCs. REPEAT the self-test.

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E5 CHECK FOR CORRECT BCM OPERATION

- Disconnect all the BCM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the BCM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?

Yes
INSTALL a new BCM. REFER to Multifunction Electronic Modules Service and Repair. TEST the system for normal operation.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.

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