VOLVO
ECM-8020 - Battery relay. Temperature too high
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
3 modelsC30 (2007–2013), S40 (2004–2013), V50 (2004–2013)
What does this fault code mean?
The battery relay disconnects the battery and starter circuit from the rest of the electrical system when the engine is restarted after an auto-stop, and the engine control module monitors it. The too-high temperature fault is probably caused by an overload in the battery relay. While the fault is active, automatic start and stop of the engine does not work. The fault applies to the C30, S40 (04-) and V50.
Possible causes
- Loose connection or oxidation in the connector
- Short circuit in the connections
- Damaged battery relay
What you can do
- 1Check that the fuses are intact
- 2Try the automatic start and stop function at idle to see whether it works
- 3Check the connections at the battery and the battery relay for looseness, contact resistance and oxidation
- 4Check that the wiring to the battery relay has no damage or short circuits
- 5If the fault remains, have a workshop with diagnostic equipment check the battery relay
Symptoms you may notice1
- Automatic engine start and stop does not work, both while driving and at idle
What the fault can affect1
- The automatic engine start and stop function is switched off
General guidance for car owners. Diagnosis on the car can point to a different cause.