What it means
The positive contactor C of the battery charging system reports a control circuit low condition. HV charging path cannot be commanded reliably.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Positive contactor C is a high-voltage switch controlled through a low-voltage circuit. The module monitors that circuit while commanding the contactor; this code sets when the circuit signal falls below its expected range, which can happen with a short to ground or excessive resistance.
Common causes
Most likely first.
- Control wire shorted to ground
- Internal short in contactor coil
- Connector pins corroded - high contact resistance
Symptoms
- Hybrid or EV system warning
- Charging may be disabled
- Vehicle may not start or enter Ready mode
How to diagnose it
- Read freeze-frame data and related codes to establish when the positive contactor C control-circuit signal went low.
- Check scan-tool command and feedback data, if available, to see whether the low signal occurs when the module commands positive contactor C.
- With the system made safe under the manufacturer's procedure, inspect the positive contactor C control wiring and connector for a ground short, damaged insulation, corrosion, or poor pin contact.
- Have a qualified technician test the control wire for an unintended connection to ground, isolating the circuit as specified by the manufacturer.
- If the wiring is sound, have the technician test the coil and connector voltage drop against the manufacturer's specification to distinguish an internal coil short from a resistive connection.
Common fixes
- Repair damaged positive contactor C control wiring that is shorted to ground.
- Clean or repair corroded or high-resistance connector pins at positive contactor C.
- Replace positive contactor C if its coil is internally shorted.
- Repair the module output circuit if testing identifies it as the source of the low signal.
Can I keep driving?
Charging may be disabled, and the vehicle may not start or enter Ready mode. Avoid relying on the vehicle until the fault is repaired; high-voltage contactor circuit work should be handled by a qualified technician.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.