Cavalier fault help please - zebedee71

I own a cavalier 1995 i.8

( C18NZ )

GM Multec CFI

Whilst driving to my sisters today the engine management light came on and the RPM dropped from around 900rpm to 400rpm.

I switched off the engine and restarted which seemed to cure the fault for a mile and again it reoccured.

When i got home and tested it i get the codes


These both seem to point to a Low Voltage fault on both sensors.

Can i ask HOW i can sort this problem out?

Is this a fault in the Sensor or perhaps a wiring fault?

Any helps would be greatly appreciated

Cavalier fault help please - zebedee71

Just to clarify

Fault codes are as follows:::

22 Throttle Potentiometer sensor (low voltage)

24 Vehicle speed sensor (no signal or low voltage)

The speedo works fine so i assume the speed sensor fault is Low voltage.

Thanks again


Cavalier fault help please - bell boy
when you say dropped 900 t0 400 do you measn while parked in neutral?
Cavalier fault help please - zebedee71

Yes while the clutch is depressed to change gear it drops or while idle at junctions


Cavalier fault help please - bell boy

at the front of the engine on the top is a cylindrical thingy with an electrical connection take the thing off the car and give it a good clean with carb cleaner.Its an idle speed control with a plunger in it that sticks.
carb cleaner in aerosol form should cost less than £3 from a motor factor
Cavalier fault help please - zebedee71
I have already stripped the sensors out cleaned them down

Also checked the plugs and wiring for damage or oil residue and any signs of tracking or shorting

I have checked the earth wires

Also the wiring loom for friction damage and holes

Still have the problem and Vauxhall want £57 just to plug it in to the computer (fuming)

I just want to know WHY i am getting a ( LOW VOLTAGE ) warning on the sensors so i can try to put it right.


Cavalier fault help please - zebedee71

It was the VSS on the back of the clocks it was fried (how i hear you ask?) well to be honest i have NO idea how but fried it was.

I had to replace the whole clocks as my clocks had the built in VSS not the interchangable one so i added 10.000 to the clock over night (and not a speed ticket in sight lol)

All done now back to normal thanks for your input lads


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