What it means
The Coolant Pump A control circuit is above the expected electrical threshold. This indicates a high circuit condition; the code alone does not identify its cause.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Coolant Pump A's control circuit carries the electrical command or supply used to operate the pump. This code indicates that the circuit is reading above its expected threshold, which can occur with a short to ground, a faulty driver stage, or poor contact resistance; the code alone does not establish which cause is present.
Common causes
Most likely first.
- Drive line shorted to ground
- Driver stage failed
- Connector pins corroded - high contact resistance
Symptoms
- Check-engine light
- Possible engine overheating or reduced cooling, if the pump is needed for engine cooling
How to diagnose it
- Check freeze-frame data and Pump A command or status to establish when the high circuit reading occurred.
- Inspect Pump A's connector and wiring for corrosion, damaged insulation, pin damage, or contact resistance at the terminals.
- Check the circuit for an unintended connection to ground using the manufacturer's wiring diagram and test procedure.
- Measure voltage drop across the Pump A power, ground, and control connections under the specified test conditions.
- If wiring and connections test correctly, verify the control-module driver output before replacing the pump or module.
Common fixes
- Clean and secure corroded Pump A connector contacts.
- Repair wiring insulation damage or a confirmed short to ground.
- Replace Pump A if testing confirms it is pulling the circuit out of range.
- Repair or replace a confirmed faulty control-module driver.
Can I keep driving?
Monitor engine temperature and avoid heavy loads until Pump A operation is confirmed, since a circuit fault may impair coolant circulation. Stop safely and switch off the engine if an overheating warning appears.
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.