Skip to content
Tahoe / Yukon Service Manual

DTC C1133 or C1134

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 C1133 Right Running Board Step Motor Hall Sensor DTC C1134 Left Running Board Step Motor Hall Sensor For symptom byte information, refer to Symptom Byte List. Diagnostic Fault Information

Circuit Short to Ground Open/High Resistance Short to Voltage Signal Performanc
Right Position Sensor Signal C1133 11 1 1 —
Left Position Sensor Signal C1134 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 The ignition is ON. Ignition voltage is between 9–16 V. The assist step disable switch is not enabled in the infotainment system. Conditions for Setting the DTC C1133 11 The K4 Running Board Control Module detects a short to ground in the running boards motor hall sensor right signal. C1134 11 The K4 Running Board Control Module detects a short to ground in the running boards motor hall sensor left signal. Action Taken When the DTC Sets The motor drive circuits are deactivated for the appropriate actuator. Conditions for Clearing the DTC The DTC becomes history when the K4 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 DTC B1B0A or B1B0B is not set ⇒ If the DTC is set Refer to: DTC B1B0A or B1B0B ⇓ If the DTC is not set
  3. A fault is currently not present and may be an intermittent condition. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. Control Module References for control module replacement, programming and setup.