Pinpoint Test E: DTC B126A:01

Handles, Locks, Latches and Entry Systems - Without Intelligent Access (IA)

Pinpoint Test E: DTC B126A:01

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

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 (Body Control Module) 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 (Body Control Module) 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 (Body Control Module)

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.

E1 CHECK THE RECORDED BCM (Body Control Module) DTCs FROM THE SELF-TEST

- Check the recorded results from the BCM (Body Control Module) self-test.

Is DTC B126A:01 present?

Yes
GO to E2.

No
CHECK the symptom(s) and GO to Symptom Chart - Electrical Without Intelligent Access (IA).

E2 CHECK THE LH DOOR LOCK CONTROL SWITCH

- Disconnect: LH Door Lock Control Switch C505.

- Repeat the BCM (Body Control Module) 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 - Edge . TEST the system for normal operation.

E3 CHECK THE RH DOOR LOCK CONTROL SWITCH

- Disconnect: RH Door Lock Control Switch C605.

- Repeat the BCM (Body Control Module) 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 - Edge . TEST the system for normal operation.

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

- Ignition OFF.

- Disconnect: BCM (Body Control Module) 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.

E5 CHECK FOR CORRECT BCM (Body Control Module) OPERATION

- Disconnect all the BCM (Body Control Module) connectors.

- Check for:
- corrosion

- damaged pins

- pushed-out pins


- Connect all the BCM (Body Control Module) 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 (Body Control Module). 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.