warning lights stuck on

[Jondotnet]

Hi Folks,

I have been struggling for a while with an older disco 2 I have parked up. It fires up instantly but the oil light wont go out.

I tried replacing the sender to see if that would help, but it hasn't

Is there a way of checking the wiring to the sender? as its a single wire, does it ground it if the pressure is above the correct level?

Also, what else could it be?

Oil pump problem?

Thanks

J

Edited to add:

This has now become a bit of a wider issue. Whilst testing the wiring (grounding the end of the wire near the sensor) I spotted that the temperature warning light was stuck on too.

So I have an oil pressure warning light and a coolant temperature warning light both that wont go out. From experience, electrical gremlins like this are sometimes caused by earth faults so is there an earth for the dash somewhere that could have got corroded?

Or any other suggestions?

Thanks

 

[German Gruner]

There is no posibility of low pressure warning&" light with corroded ground lines. You must check oil pressure or mount a new oil pressure to see if present sensor is giving wrong alert at pressure higher to 5 PSI levels.
And check temp too, prior to believe sender is not working ok.

Regards

 

[rovercanus]

Check the wiring going to the sensor. It can rub and have a bare spot . If it grounds out it can send you a false signal.
But as Gruner suggested, better check your oil pressure.

 

[Jondotnet]

I have checked the oil pressure and its OK. The temperature warning light is on as well but the engine is cold

Engine is fine, just need to figure out why both warning lights are stuck on. Had a quick look at the wiring and cant see anything obvious

 

[German Gruner]

If pressure is good, you can follow diagnostic in this way: You may try pulling oil pressure sensor cable to disconnect it. If light goes off after disconnect, then your sensor is kaputt. If light still remains on, then your cables are touching ground thru an insulation damage.

Regards

 

[Jondotnet]

Finally found some time to look further into this.

I have put a pressure gauge on to the pressure sender port and the oil pressure is fine. I have also tried a spare set of clocks and get the same two warning lights.

Its a bit of a mystery!

Going to try and find any cable damage on the oil pressure side but stumped on the coolant temp warning light given the gauge shows cold

 

[WaltNYC]

What does live OBD data indicate for coolant temp?

FWIW, I've been struggling with temp sensors for the intake on my P38 (same Bosch engine as the D2). Genuine sends signal to BECM that is 5-7 degrees LOWER than actual (measured with an IR gun at the coolant output tube of the inlet manifold) while All Makes brand sends signal interpreted by the BECM as 10-13 degree HIGHER than actual. And when using the All Makes sensor the dash gauge is not functional while the genuine Rover sensor is agreeable to the gauge on the cluster.

Additionally, with SAI, the BECM compares the temp sensor at the bottom of the radiator to the sensor at the intake manifold to determine whether the thermostat is functioning properly. If those two temps are too close, an error code is generated and the 'service engine' light on the dash appears. The genuine temp sensor, reading low as it does, generates a code and light. I need to find a different brand sensor to see if I can find one that is accurate, agreeable to the cluster gauge, and won't throw a code. Fortunately I can swap them in less than 10 minutes.

 

[mbrummal]

The P38 uses a temp sensor with 2 different thermistors, one for the ECU and one for the gauge cluster. The "bad" allmakes sensor might just be for a D2 that only uses one thermistor for the ECU that it then sends to the gauge cluster. The RAVE Manual mentions it in the Fuel System section of the workshop manual.