OVP relay?

[Iain the gadget]

C200 sport auto 2000

Rough running,not revving over 2500, disconnected MAF so it runs off ECU settings and still no change. I have read some posts which mention the OVP relay. What does OVP stand for? What function does it perform? and where is it located please?
All suggestion gratefully received.

 

[television]

OVP over voltage protection relay, a device to protect the expense ECU's in your car.

http://www.detali.ru/cat/oem_mb2.as...417717.418&CT=F&cat=45H&SID=54&SGR=045&SGN=05

Its Item 128 where fitted.

Malcolm

 

[Iain the gadget]

Thanks Malcolm. Would this cause the symptoms that I've described if it was faulty?
I have read that disconnecting a faulty MAF will restore reasonable running of the ECU. Is this correct?
Value your knowledgable opinion.
Iain

 

[television]

Hi Ian, disconnecting the MAF will normally let the car run better if it was faulty in the first place.

If the running is poor the OVP relay can cause this as the ECU are running on 7.5 volt as against the 12volt. There is a fuse on top of the relay, if you have a voltmeter there should be 12v on both sides of the fuse.

Malcolm

 

[eric242340]

OVP relay

The OVP relay is ( Overvoltage Protection Relay) and no it should not subscribe to your present problem. Disconecting the MAF usually results in the ECU using a back-up system and as you say it has no effect. I think you can discount both the MAF and OVP as the cause of the problem.

 

[Iain the gadget]

Thanks Malcolm.
I'll look at this and get back with my findings. As along as I don't get swept away by the gales!

Is that 12volts running or just with ignition on?

 

[television]

Thanks Malcolm.
I'll look at this and get back with my findings. As along as I don't get swept away by the gales!

Is that 12volts running or just with ignition on?

Just with the ignition on, key 2

Malcolm

 

[Iain the gadget]

Apparentlly year 2000 cars with the short stubby infra-red key don't have them. OVP's that is!

 

[television]

Sorry about that,always hard without a VIN,more so on the C class
Then it is time to check the MAF.

Waiting for answer back They dont have one , some cars do not


malcolm

 

[Iain the gadget]

Malcolm.
Just bought a Genuine MB MAF off ebay £62 with free p+p.
Probably receive it next monday. I'll post back after it's fitted and many thanks for your advice.
Iain

 

[YoYo_Balls]

C200 sport auto 2000

Rough running,not revving over 2500, disconnected MAF so it runs off ECU settings and still no change. I have read some posts which mention the OVP relay. What does OVP stand for? What function does it perform? and where is it located please?
All suggestion gratefully received.

sounds like your car has went into limp mode because there is a fault this resulting in it not reving properly dont think there is a ovp relay if it's a w203 model

 

[Iain the gadget]

No its a W202 with no OVP
Limp mode wouldn't cause the rough running like it is.