Liftgate Mode Switch Circuit Performance Signal Invalid
Table of contents
B396C GMC Possible Causes
- Faulty Liftgate Control Switch-Interior
- Liftgate Control Switch-Interior harness is open or shorted
- Liftgate Control Switch-Interior circuit poor electrical connection
- Faulty Liftgate Control Module
How do I fix code B396C GMC?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Cost of diagnosing the B396C GMC code
The cost of diagnosing the B396C GMC code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
B396C GMC Description
The interior liftgate rotary control switch contains 3 resistors which are in series for the liftgate mode, depending upon which position is selected will determine which combination of resistors are used. The liftgate module monitors the voltage level in the liftgate mode signal circuit, as each mode is selected, the voltage within the signal circuit incrementally drops. It is this method the liftgate module will determine if mode switch is in the manual mode, garage mode or the maximum open mode.
The interior liftgate control switch has of a push button switch to command the liftgate to open and close. The liftgate module monitors the voltage level on the open/close signal circuit, when the switch is not being pressed the voltage level is at the system voltage. When the switch is pressed a contact within the interior liftgate control switch closes providing a ground path for the signal circuit causing the voltage level to drop to near zero volts. The liftgate module will detect the voltage drop and will then command the liftgate to open or close depending upon the current state of the liftgate at the time the switch is pressed.
The Diagnostic Trouble Code (DTC) sets when the liftgate control module detects an out of range condition in the mode switch signal circuit.