Code 54 (DME Power Supply)
CONTROL UNIT SUPPLY VIA MAIN RELAYExplanation
This trouble code is stored when the voltage supply exceeds 16 V. A drop in the voltage supply below 9 V is detected 3 min after the start at the earliest.
Troubleshooting
- Check battery acid level
- Check charged battery under load
- Check B+ wire to the Digital Motor Electronic (DME) relay
- Check charging current of alternator with consumer loads switched on
- Check voltage regulator
- Proceed with displayed scan tool diagnostic instructions where applicable.