Vauxhall Cavalier 1995 2.0i CDX Ecotec - ECU fault codes - peter973

How do I check the ECU Fault Codes ?

I am having intermittent starting problem over last 3 days with Engine Control Indicator (lightning symbol) on instrument panel flashing at times.

Car starts for while, then won't start for a while, then starts, over an hour period of testing.

I read in the past somewhere, you can check ECU fault Codes on a plug by shorting 2 pins.

I had a look for a plug that might be it, but can't find it.

Anyone know where this plug is, how I check the fault codes and tell what they mean ?

Thanks

Edited by peter973 on 01/05/2015 at 23:05

Vauxhall Cavalier 1995 2.0i CDX Ecotec - ECU fault codes - elekie&a/c doctor
There is a 10 pin diagnostic socket under the bonnet ,located adjacent to the left suspension strut.It is usually docked in a plastic recess.Bridging pins A and B with a paper clip with ignition on will give you some flash codes.However ,you say that the mil light flashes which could indicate a fault with the immobiliser or chipped key.Does your car have the additional Bosch immobiliser system fitted?
Vauxhall Cavalier 1995 2.0i CDX Ecotec - ECU fault codes - peter973

Yes, I have Immobiliser fitted and need to use chipped key to start car.

Problem is intermittent, not consistent, seems to vary.

On Wednesday
Had driven short distance round block, as car pulled in, engine cut out.
Car would not start for period, then started, drove car round block to test.
No problem getting steady Engine Control Indicator, which indicates ok to start.

On Thursday
Car started, then would not start for period, then started.
No problem getting steady Engine Control indicator, which indicates ok to start.

on Friday (yesteday)
Car started, ran for few minutes, stopped.
Could not start for few hours.

Could not get steady Engine Control Indicator for few hours (different to Thu/Fri).
Seemed to have slightly different flash sequence, with 2-3 faster flashes in sequence.

After few hours, car started, then no problem getting car to start and no problem getting steady Engine Control Indicator.

Very odd & inconsistent.

PS: what does mil stand for ?

Edited by peter973 on 02/05/2015 at 16:05

Vauxhall Cavalier 1995 2.0i CDX Ecotec - ECU fault codes - elekie&a/c doctor
The most common issue on these for cutting out is a faulty crankshaft sensor,or faulty efi/pump relay.MIL is malfunction indication light (or mother in law)
Vauxhall Cavalier 1995 2.0i CDX Ecotec - ECU fault codes - peter973
The most common issue on these for cutting out is a faulty crankshaft sensor,or faulty efi/pump relay.MIL is malfunction indication light (or mother in law)

The problem has reappeared, with engine running for fraction of second on starting, even little longer if I pump the pedal.

It seems fuel problem may be possibility, as engine does run for very short period.

You say faulty EFI/PUMP RELAY is common issue.

Is this one issue or two, that is Electronic Fuel Injection Pump Relay as 1 issue, or EFI in general & Pump Relay as 2 issues ?
.
.
Should the fuel rail be continually pressurised when ignition is on & ready to start ??

I checked fuel rail bleed valve with ignition on & ready to start.

When I press fuel rail bleed valve, a small burst of fuel comes out, then ends rapidly.
.
.
Is that right or should fuel rail be continually pressuried with fuel coming out continually from bleed valve ??

.

Edited by peter973 on 08/05/2015 at 20:51

Vauxhall Cavalier 1995 2.0i CDX Ecotec - ECU fault codes - peter973
There is a 10 pin diagnostic socket under the bonnet ,located adjacent to the left suspension strut.It is usually docked in a plastic recess.Bridging pins A and B with a paper clip with ignition on will give you some flash codes.However ,you say that the mil light flashes which could indicate a fault with the immobiliser or chipped key.Does your car have the additional Bosch immobiliser system fitted?

I found the Diagnostic Socket.

Most of the contacts have what appears surface corrosion, doesn't look easy access to clean up, as contacts are hidden within socket.

Also seem to be 2 pins in docking recess, seem to be locating pins to hold socket rather than electrical contacts, no wires underneath. Engine runs with socket out/undocked, so assume corrosion on socket contacts can't be causing problem.

Vauxhall Cavalier 1995 2.0i CDX Ecotec - ECU fault codes - peter973

<<The most common issue on these for cutting out is a faulty crankshaft sensor,or faulty efi/pump relay.MIL is malfunction indication light (or mother in law)>>
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The problem has reappeared, with engine running for fraction of second on starting, even little longer if I pump the pedal.

It seems fuel problem may be possibility, as engine does run for very short period.

You say faulty EFI/PUMP RELAY is common issue.

Is this one issue or two, that is Electronic Fuel Injection Pump Relay as 1 issue, or EFI in general & Pump Relay as 2 issues ?
.
.
Should the fuel rail be continually pressurised when ignition is on & ready to start ??

I checked fuel rail bleed valve with ignition on & ready to start.

When I press fuel rail bleed valve, a small burst of fuel comes out, then ends rapidly.
.
.
Is that right or should fuel rail be continually pressuried with fuel coming out continually from bleed valve ??

.

Edited by peter973 on 09/05/2015 at 01:25