DTC B1B0A or B1B0B

Diagnostic Instructions Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Review Strategy Based Diagnosis for an overview of the diagnostic approach. Diagnostic Procedure Instructions provides an overview of each diagnostic category. DTC Descriptors DTC B1B0A 11 Articulating Running Board Motor Hall Sensor Right Reference short to ground. DTC B1B0B 11 Articulating Running Board Motor Hall Sensor Left Reference short to ground. Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performanc
Running Boards Motor Hall Sensor Right Reference	B1B0A 11	1	1	—
Running Boards Motor Hall Sensor Left Reference	B1B0B 11	1	1	—
Right Position Sensor Signal	B1B0A 11 C1133 11	1	1	—
Left Position Sensor Signal	B1B0B 11 C1134 11	1	1	—
Running Boards Motor Hall Sensor Right Low Reference	—	B1B0A 11 1	1	—
Running Boards Motor Hall Sensor Left Low Reference	—	B1B0B 11 1	1	—
1.	Running board motor inoperative

Circuit/System Description The running board control module controls the running board actuators to extend or retract the running boards. Each actuator consists of an electric motor and a hall-effect switch. The module supplies a low reference and battery voltage reference source to the hall-effect switch. The running board control module monitors the signal from the hall effect switch on the signal circuit. When the actuator shaft rotates, the hall-effect switch provides pulses to the running board control module which uses the pulses as counts to determine the location of the assist steps. The running board control module supplies the actuator motor with a PWM 12 V control circuit and a ground control circuit. The running board control module controls the direction of the actuator by changing the polarity of the control circuits. Conditions for Running the DTC Co d t o s o u g t e C The ignition is ON. Ignition voltage is between 9–18 V. Conditions for Setting the DTC B1B0A 11 The K4 Running Board Control Module detects a fault on the right hall effect sensor reference voltage circuit. B1B0B 11 The K4 Running Board Control Module detects a fault on the left hall effect sensor reference voltage circuit. Action Taken When the DTC Sets The motor drive circuits are deactivated for the appropriate running board step. Conditions for Clearing the DTC The DTC becomes history when the running board control module no longer detects the condition that set the DTC. The history DTC will clear after 40 fault free ignition cycles. Reference Information Schematic Reference Step/Running Board Schematics Connector End View Reference Master Electrical Component List Description and Operation Running Board Description Electrical Information Reference Circuit Testing Connector Repairs Testing for Intermittent Conditions and Poor Connections Wiring Repairs Scan Tool Reference Control Module References for scan tool information Circuit/System Verification

1. Ignition ON.
2. Verify using the infotainment system menu that the automatic running boards are enabled. ⇒ If the running boards are disabled Enable the running boards by navigating to the switch integrated into the infotainment system. ⇓ If the running boards are enabled
3. Verify the left side running board extends and retracts when opening and closing the left side doors, and the right side running board extends and retracts when opening and closing the right side doors. ⇒ If either of the running boards do not extend or retract Perform Circuit/System Testing ⇓ If the running boards extend and retract
4. A fault is currently not present and may be an intermittent condition Circuit/System Testing
5. Ignition OFF, doors closed, and all vehicle systems OFF. It may take up to 2 min for all vehicle systems to power down. Disconnect the appropriate in-line harness connector: M95L Assist Step – Left M95R Assist Step – Right

Note

When disconnecting a running board step, C1180 or C1183 will set for the running board disconnected.

2. Test for less than 10 Ω between the low reference circuits listed below ground. M95L Assist Step – Left – Low reference circuit terminal 4 M95R Assist Step – Right – Low reference circuit terminal 4 ⇒ If 10 Ω or greater 2.1. Ignition OFF, disconnect the harness connector at the K4 Assist Step Control Module. 2.2. Test for less than 2 Ω in the low reference circuit end to end. ⇒ If 2 Ω or greater, repair the open/high resistance in the circuit. ⇒ If less than 2 Ω, replace the K4 Assist Step Control Module. ⇓ If less than 10 Ω
3. Ignition ON.
4. Test for 9 V or greater between the appropriate reference circuit terminal listed below and ground while commanding the appropriate Assist Step Motor to Extend and Retract with the scan tool. M95L Assist Step – Left – voltage reference circuit terminal 2 M95R Assist Step – Right – voltage reference circuit terminal 2 ⇒ If less than 9 V 4.1. Ignition OFF, disconnect the X3 harness connector at the K4 Running Board Control Module. 4.2. Test for infinite resistance between the voltage reference circuit terminal and ground. ⇒ If less than infinite resistance, repair the short to ground on the circuit. ⇓ If infinite resistance 4.3. Test for less than 2 Ω in the voltage reference circuit end to end. ⇒ If 2 Ω or greater, repair the open/high resistance in the circuit. ⇒ If less than 2 Ω replace the K4 Running Board Control Module. ⇓ If 9 V or greater
5. Test for 9 V or greater between the appropriate signal circuit terminal listed below and ground while commanding the Assist Step Motor to Extend and Retract with the scan tool.

Note

The voltage reading will appear momentarily while toggling back and forth between Extend and Retract with a scan tool. After 4 tries, you must wait at least 10 s to repeat. M95L Assist Step – Left – Signal circuit terminal 3 M95R Assist Step – Right – Signal circuit terminal 3 ⇒ If less than 9 V 5.1. Ignition OFF, disconnect the X3 harness connector at the K4 Running Board Control Module. 5.2. Test for infinite resistance between the signal circuit terminals and ground. ⇒ If less than infinite resistance, repair the short to ground on the appropriate circuit. ⇓ If infinite resistance 5.3. Test for less than 2 Ω in the signal circuits end to end. ⇒ If 2 Ω or greater, repair the open/high resistance in the circuit. ⇒ If less than 2 Ω replace the K4 Running Board Control Module. ⇓ If 9 V or greater.

6. Ignition OFF, connect the in-line harness connector.
7. Ignition ON, clear the DTC.
8. Verify the DTC does not reset while commanding the assist step to extend and retract using the scan tool or assist step switch. ⇒ If the DTC resets 8.1. Replace the appropriate M95 Assist Step. 8.2. Verify the DTC does not reset. ⇒ If the DTC resets, replace the K4 Running Board Control Module. ⇓ If the DTC does not reset All OK. ⇓ If the DTC does not reset
9. All OK. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. Assist Step Motor Replacement Control Module References for control module replacement, programming and setup.