Pinpoint Test Aa: DTC B126A:01

WARNING: This page is about a different car, the 2014 Lincoln MKX and 2014 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.

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

AA1 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 AA2.
- No : CHECK the symptom(s) and GO to SYMPTOM CHART - ELECTRICAL .
AA2 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 AA3.
- No : INSTALL a new LH door lock control switch. REFER to DOOR LOCK CONTROL SWITCH - EDGE or DOOR LOCK CONTROL SWITCH - MKX . TEST the system for normal operation.
AA3 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 AA4.
- No : INSTALL a new RH door lock control switch. REFER to DOOR LOCK CONTROL SWITCH - EDGE or DOOR LOCK CONTROL SWITCH - MKX . TEST the system for normal operation.
AA4 CHECK THE LOCK INPUT CIRCUIT OR THE UNLOCK INPUT CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: BCM C2280C .
- For Edge, 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.
  
  Fig 1: Measuring Resistance Between LH Door Lock Control Switch C605-1, Circuit CPL42 (BU/GN) And Ground
  Courtesy of FORD MOTOR CO.
- For MKX, measure the resistance between the RH Door Lock Control Switch C605-1 , circuit CPK23 (YE/VT), harness side and ground; and between the RH Door Lock Control Switch C605-3 , circuit CPK19 (BU/GN), harness side and ground.
  
  Fig 2: Measuring Resistance Between RH Door Lock Control Switch C605-1, Circuit CPL42 (YE/VT) And Ground
  Courtesy of FORD MOTOR CO.
Are the resistances greater than 10, 000 ohms?
- Yes : GO to AA5.
- No : REPAIR circuit CPK19 (BU/GN) or circuit CPK23 (YE/VT) for a short to ground. CLEAR the DTCs. REPEAT the self-test.
AA5 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 . 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.