What it means
Voltage on the charge status indicator a control circuit is above the expected window. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
At a glance
- Usually lights the check-engine light
How it works
Charge status indicator A is operated through its dedicated control circuit. The control module monitors circuit A voltage, and P0E40 sets when it rises above the expected window, which can point to a short to battery positive, an open indicator, or a poor connector contact.
Common causes
Most likely first.
- Wire shorted to B+
- Open lamp
- Connector pins corroded - high contact resistance
Symptoms
- Charge status indicator may not illuminate or may behave unexpectedly
- Hybrid/EV system warning light may turn on
How to diagnose it
- Record freeze-frame data and check live voltage or command data for charge status indicator A when the fault is present.
- Inspect indicator A and its connector for an open indicator, corrosion, water ingress, loose pins, or harness damage.
- Check circuit A for a short to battery positive and inspect for chafing against powered wiring.
- Test indicator A for an open circuit and check connector terminal contact using the manufacturer’s procedure.
- Measure circuit voltage and continuity under specified conditions and compare with the manufacturer’s specification.
Common fixes
- Repair wiring shorted to battery positive in charge status indicator A’s circuit.
- Repair loose, corroded, or water-damaged connector terminals.
- Replace indicator A if it is open or otherwise failed.
- Confirm circuit A voltage and indicator operation after repair.
Can I keep driving?
Charge status indicator A may not work as expected, but the code alone does not confirm whether charging is affected. Verify charging through the vehicle or charging equipment display, and stop if a charging or high-voltage system 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.