What it means
The control circuit for negative contactor A in the battery charging system is below its expected electrical range. The fault can prevent reliable contactor control.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Negative contactor A's control circuit operates the high-voltage switch in the battery charging system. P0D13 sets when the module sees the circuit signal below its expected electrical range, which can happen if the wire is grounded, the coil is internally shorted, or a poor connection lowers the signal.
Common causes
Most likely first.
- Wire shorted to ground
- Internal coil short
- Connector pins corroded - high contact resistance
Symptoms
- Charging system warning light may come on
- Charging may not start or may stop unexpectedly
- Reduced electric driving range
How to diagnose it
- Save freeze-frame data and related codes, then check whether the low reading occurred while negative contactor A was commanded on or off.
- Inspect the contactor connector and harness for a wire rubbed through to ground, corrosion, or damaged terminals.
- Use the wiring diagram to test the control circuit for an unintended ground and check connector contact quality.
- Measure the contactor coil and circuit response under the manufacturer's test conditions to check for an internal short or excessive resistance.
- If wiring and coil tests pass, compare module command and circuit feedback to identify a possible driver fault.
Common fixes
- Repair a control wire that is shorted to ground.
- Clean or replace corroded connector pins causing high contact resistance.
- Replace negative contactor A if its coil is internally shorted.
- Repair the control-module driver only after confirming the harness and contactor are within specification.
Can I keep driving?
The low control signal can prevent charging or interrupt it, reducing electric range. Avoid relying on the vehicle for a charge-dependent journey while the warning is active.
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.