[Mikexx]

I intended to measure voltage to see if there was indeed power to the plugs, and if there was a voltage drop valve nice the relay kicked in as I would expect to find.. not that I have much knowledge..

Hence I was shocked to find 10,8V at the plugs which didn’t drop but rose when ignition turned on!

Am I right in thinking that.. my fault code suggests an open circuit, and given I have voltage at the plugs even when ignition is off, that the glow plug circuit is open and therefore faulty?

It is possible there is a modest leakage across the relay contacts as you're measuring the voltage without a load. The meter you are using is very high impedance, so a minute leakage across the relay will show near battery volts. A few 10s of uA will do it.

When you turned the 'ignition' on and it went up slightly provides further evidence of the leakage and that the relay may well be working.

The best test is made under load. Use a small bulb instead of the glowplug, or better still if you can measure volts when the glowplug connected with the ignition off and on.

The P0045 indicates a faulty sensor/circuit somewhere and may or may not be connected with the GP relay. The GP issue may be a red herring.

 

[Dazz]

A small bulb between ground and gp cap

It is possible there is a modest leakage across the relay contacts as you're measuring the voltage without a load. The meter you are using is very high impedance, so a minute leakage across the relay will show near battery volts. A few 10s of uA will do it.

When you turned the 'ignition' on and it went up slightly provides further evidence of the leakage and that the relay may well be working.

The best test is made under load. Use a small bulb instead of the glowplug, or better still if you can measure volts when the glowplug connected with the ignition off and on.

The P0045 indicates a faulty sensor/circuit somewhere and may or may not be connected with the GP relay. The GP issue may be a red herring.

??

A small bulb between ground and gp cap?

I don’t think I will be able to get to plugs while connected, they are a pig to get to!

Think I’ll try take a reading with relay unplugged too just to check not getting voltage at caps.

Will update as soon as I can get it done.

 

[Dazz]

It is possible there is a modest leakage across the relay contacts as you're measuring the voltage without a load. The meter you are using is very high impedance, so a minute leakage across the relay will show near battery volts. A few 10s of uA will do it.

When you turned the 'ignition' on and it went up slightly provides further evidence of the leakage and that the relay may well be working.

The best test is made under load. Use a small bulb instead of the glowplug, or better still if you can measure volts when the glowplug connected with the ignition off and on.

The P0045 indicates a faulty sensor/circuit somewhere and may or may not be connected with the GP relay. The GP issue may be a red herring.

Update-

Bought another relay and fitted that.. tried with same tester and got same results.. however!

Then made a little test lamp and tested glow plug caps with the lamp which doesn’t light up until I turn ignition on.

So, you were right, **** tester and glow plugs and relay working as they should so defintaly a red herring!

Only fault code still the p0679 open circuit somewhere..

Have checked all connections and wiring that I can see and all seem ok!?

Help!

 

[Mikexx]

Update-

Bought another relay and fitted that.. tried with same tester and got same results.. however!

Then made a little test lamp and tested glow plug caps with the lamp which doesn’t light up until I turn ignition on.

So, you were right, sugar tester and glow plugs and relay working as they should so defintaly a red herring!

Only fault code still the p0679 open circuit somewhere..

Have checked all connections and wiring that I can see and all seem ok!?

Help!

That's a good move. Does the van run ok in every other respect? Does the lamp turn off after a few seconds of ignition without cranking?

Some sensors don't immediately report an error, some go away after a period of time. I would run the vehicle and check for fault codes at some point in the future to see if there is any change. I might not expect P0679 to exist alone without some other fault code associated with the offending sensor.

When I looked up P0679 I got conflicting results like:
http://p0679.enginecoderepair.com/
http://p0679.engine-trouble-code.com/

If the fault code exists by itself after a week or more of running I might give your 'friendly' Vauxhall dealer a ring and ask them to explain the fault code and what sensor it applies to. It may be more than one.

 

[Dazz]

That's a good move. Does the van run ok in every other respect? Does the lamp turn off after a few seconds of ignition without cranking?

Some sensors don't immediately report an error, some go away after a period of time. I would run the vehicle and check for fault codes at some point in the future to see if there is any change. I might not expect P0679 to exist alone without some other fault code associated with the offending sensor.

When I looked up P0679 I got conflicting results like:
http://p0679.enginecoderepair.com/
http://p0679.engine-trouble-code.com/

If the fault code exists by itself after a week or more of running I might give your 'friendly' Vauxhall dealer a ring and ask them to explain the fault code and what sensor it applies to. It may be more than one.

Van runs fine other than the light on..

It doesn’t go off at all regardless how long I leave the ignition on without turning the engine.

I only really need to clear the dash lights to get an MOT and sell on but might have to run it a while 1st and hope a further code develops

 

[Fred Bassett]

I know he said he's sorted the boost sensor.

Perhaps it's just a coincidence as P0697 implies an open circuit sensor and there are no other fault codes to suggest any other sensor that the one that's been changed.

The need to repair a wire is worrying. I'm wondering if this has touched anything such as earth and damaged the ECU?

These are known for wiring loom getting chaffed under the air box.

 

[Mikexx]

Van runs fine other than the light on..

It doesn’t go off at all regardless how long I leave the ignition on without turning the engine.

I only really need to clear the dash lights to get an MOT and sell on but might have to run it a while 1st and hope a further code develops

This may sound really stupid, but with the OBD reader attached, did you try and reset this code? Most codes disappear for a while before reappearing.

 

[Dazz]

This may sound really stupid, but with the OBD reader attached, did you try and reset this code? Most codes disappear for a while before reappearing.

Yes reset the code via the reader but says cleared then reappears instantly.

 

[Fred Bassett]

In reference to the diagnostic trouble code did it state wether the voltage was high or low ?

 

[Dazz]

In reference to the diagnostic trouble code did it state wether the voltage was high or low ?

No wasn’t that specific.

 

[Dazz]

So checking all the relays I found this....
Burn marks withing the connector!!

Anyone know what circuit this operates?

 

[Fred Bassett]

It says 60amp on the relay , could be for the heated windscreen .
What number does it say it is in the handbook ?

 

[Dazz]

It says 60amp on the relay , could be for the heated windscreen .
What number does it say it is in the handbook ?

Don’t have the manual.. and everywhere I have looked doesn’t say!!

It is the only 60amp... don’t have a heated screen!

 

[Fred Bassett]

Ok leave it unplugged & see what doesn’t work.

 

[Dazz]

Not starting at all now

 

[Fred Bassett]

Not starting at all now

So it must be something to do with the fuel injection management system then , when plugged back in does the van start ok ?

 

[Dazz]

Changed the relay and connector... van starts but warning lights and code still coming up..

Guess I’ll have to run it for a while and see if it throws another code alongside the p0679.

Failing that will have to go in to garage to find which circuit it is

 

[Dazz]

FIXED!!!

Took the van in and it transpires that the after market mass air flow sensor I put on was throwing all the values out and causing the issue.

Put on a Bosch mass air flow sensor and boom all sorted and working... no more dash lights or faults!

Beware cheaper after market parts lesson learnt.