OBD-II · Engine and powertrain (P)
P0620
Generator control circuit
What it means
The ECU detects a fault in the circuit it uses to control the alternator's charging voltage.
Symptoms
- battery warning light
- start-stop stops working
- slow cranking or no start
- dim lights or electrical glitches
- engine warning light
Likely causes, most likely first
| No. | Cause |
|---|---|
| 01 | alternator connector or wiring fault |
| 02 | faulty alternator regulator |
| 03 | LIN communication fault with the alternator |
| 04 | ECU driver fault |
What to check, step by step
- 01Inspect the alternator connector and control wire
- 02Check charging voltage at idle and 2,000 rpm
- 03Check for communication codes involving the alternator
- 04Replace the regulator or alternator if the wiring is good