Overvoltage Protection Relay (201 540 3745)
201 540 3745|
201 540 3045
The Overload Protection (OVP) Relay is a relay used to protect the computer components of a vehicle. On the 190E and 300E, it serves to protects the main ECU and the ABS computer. The newer version of the OVP with the red cap has two 10A fuses on top while the older black cap version has only one 10A fuse. Cars originally equipped with the black cap can upgrade to the newer red capped version.
Removal / Installation
W201 / W124
- Remove battery
- Remove electronics cover behind battery
- Unplug OVP relay
- Remove OVP relay
- Installation is reverse order
ABS light on
If the ABS light is illuminated in the instrument cluster and the engine is running, it is common to find that the culprit is the OVP relay. The ABS computer will not receive any power if the OVP relay is not functioning correctly, therefore triggering the warning light. Check the fuse(s) on top of the OVP relay for any cracks or run a continuity test. Lastly, replace the OVP relay with a known working unit.
Hard to start
Difficulties starting can also signal a bad OVP relay. The main ECU will not receive power if the OVP is not functioning correctly. Check the fuse(s) on top of the OVP relay for any cracks or run a continuity test. Lastly, replace the OVP relay with a known working unit.