Test A: The Retractable Running Board Does Not Operate Correctly - Both Running Boards

PINPOINT TEST A: THE RETRACTABLE RUNNING BOARD DOES NOT OPERATE CORRECTLY - BOTH RUNNING BOARDS

A1:

A2-A6:

A6-A7:

A7-A8:

A8-A11:

NOTE: If any door ajar or VSS related DTCs are present, diagnose the door ajar and VSS related DTCs before performing this pinpoint test.

Normal Operation
The power liftgate module, which controls the LH and RH retractable running board motors, receives battery voltage at all times through circuits 1246 (LG/RD) and 729 (RD/WH), and is grounded through circuit 57 (BK). The LH and RH retractable running board motors receive battery voltage at all times through circuit 1943 (RD/WH) and ground through circuit 57 (BK).

The message center is used to turn the retractable running board system ON/OFF or set the mode of operation to AUTOMATIC/IN or MANUAL/OUT. When the retractable running board system is set to AUTOMATIC/IN mode, the retractable running boards will remain retracted while the doors are closed. When a door is opened, the retractable running board on the same side will deploy. When the door is closed, the running board will retract. When the retractable running board system is set to MANUAL/OUT mode, both retractable running boards will remain deployed at all times regardless of any door being OPEN or CLOSED. The message center transfers the retractable running board information to the instrument cluster module (ICM) through circuits 1411 (GY/OG) and 1396 (VT/WH). The instrument cluster module (ICM) transfers the retractable running board information to the power liftgate module (PLGM) through medium speed controller area network (MS CAN) circuits 2180 (WH/BK) and 2181 (BK/YE).

When the retractable running board system is in AUTOMATIC/IN mode, and a door is opened, the corresponding door ajar switch will provide a ground signal to the vehicle security module (VSM) through circuit 344 (BK/YE) for the LH front door, 346/363 (BK/WH)/(BK/LB) for the LH rear door, 345 (BK/PK) for the RH front door or 346 (BK/WH) for the RH rear door. When the VSM receives a ground signal from a door ajar switch, the VSM will transfer the door ajar status to the PLGM through the MS CAN network. When the PLGM receives the door ajar information from the VSM, the PLGM will command the corresponding retractable running board to deploy by sending a ground signal to the LH retractable running board motor through circuit 1944 (BN/PK) or to the RH retractable running board motor through circuit 1945 (PK/WH).

Possible Causes
- Fuse
- Open in circuits 1943 (RD/WH), 1944 (BN/PK), 1945 (PK/WH) or 57 (BK)
- Vehicle security module (VSM)
- Door ajar switch
- Power liftgate module (PLGM)
- Powertrain control module (PCM)
- Instrument cluster module (ICM)