C116A Code: Meaning, Causes, and Symptoms | OBD2 Codes

C116A – ABS Pressure Transducer/Brake Switch Mismatch


C116A Possible Symptoms


Anti-Lock Brake System (ABS) Warning Light ON,Engine Light ON (or Service Engine Soon Warning Light)


C116A Possible Causes


Faulty Hydraulic Control Unit (HCU),Hydraulic Control Unit (HCU) harness is open or shorted,Hydraulic Control Unit (HCU) circuit poor electrical connection


C116A Description


The pressure transducer is integral to the Hydraulic Control Unit (HCU). The pressure transducer sends a signal to the ABS module that varies in relation to the amount of pressure applied to the brake pedal. The more pressure that is applied, the greater the signal sent to the Anti-Lock Brake System (ABS) module. If a new pressure transducer is needed, then a new HCU must be installed. When the brake pedal is pressed, the stop lamp switch closes and a voltage is sent to the Powertrain Control Module (PCM). The PCM then sends a message over the High-Speed Controller Area Network (HS-CAN) to the ABS module indicating that the brake pedal has been pressed. DTCs set in the ignition cycle can only be cleared by cycling the ignition off and on once the fault has been corrected. This DTC sets in every ignition cycle if during normal operation, the stop lamp switch message does not match the HCU transducer, both signals have to agree about whether the brakes are being applied or not.