Vauxhall Astra G

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Vauxhall Astra G

Postby Technician » Wed Jul 22, 2015 10:14 pm

Bit of an old car these days, but people still require them repairing where it is cost effective to do so.

I had an Astra G 1998 2.0 Di dropped on me today, the car will not start, cranks ok but that is it.

I checked for codes using TECH II and was presented with P1631 (B) fuel injection control module 3. TECH II advised that the code is "Not Present".

Looking at Autodata wiring diagram I established that the fuel injection control module terminal 7 had battery voltage present by back - probing at the connector, and that terminal 6 had 0V present with the ignition switched on.

I got to see that the fuel injection control module has a wire in terminal 1, but Autodata wiring diagram has not got this wiring connected to the control unit?

I disconnected the fuel injection control connector and the ECM connector and carried out volt drop testing on the remaining 4 wires between the two control units, using the Snap On Hook. I did not find a fault with the wiring.

Looking at Autodata pin data the ECM terminal 91 appears to be providing an output signal that should be measured using a scope, I do have a scope but as the engine will not start I felt that test was pointless, please advise if anyone thinks otherwise.

According to Autodata pin 99 has a typical voltage present of 1.5 - 2.5v when the engine is idling, however their wiring diagram has omitted this wire between the two control units, and as the engine does not run I felt that this circuit I could not test it.

With regards to ECM pin 100, Autodata advise that a voltage of 2.5V should be seen, however a voltage of 00.04v was seen.

I rang Vauxhall and spoke to the workshop foreman about my concerns, he advised that the Vauxhall checking procedure with regards to the ECM pins 99, 100 and ground should produce a ohm reading greater than 500 kOhm.

So I disconnected the ECM connector and checked the resistance between 99 and ground, and 100 and ground, both wires circuits recorded a ohm reading of 1.065 kOhm

Because this resistance test appears to be testing the Fuel injection control module, and the resistance appears significantly out of range, and that the voltage readings on pins 1 and 2, I am leaning towards the understanding that these pins 1 and 2 are providing output signals from the Fuel Control unit to the ECM and this is the cause of the none start.

A new Fuel Injection Control unit appears to me to be required, but I could be wrong, has anyone got any advice please as I have done about the best I can.
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Re: Vauxhall Astra G

Postby Robski » Thu Jul 23, 2015 8:43 am

has anyone got any advice please as I have done about the best I can.

yes consult TIS for yourself.

Also if the code is not present then does it return KOEO or KOEC ?

Oh & no mention of data stream neither ?

I almost forgot, with the correct equipment you can read the pump controller for DTC's.
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Re: Vauxhall Astra G

Postby Technician » Thu Jul 23, 2015 6:31 pm

Robski wrote:
has anyone got any advice please as I have done about the best I can.

yes consult TIS for yourself.

Also if the code is not present then does it return KOEO or KOEC ?

Oh & no mention of data stream neither ?


Was initially having problems with TIS hence asking Vauxhall, however I have now got TIS up and running.

The code is not present and after clearing and KOEC yes the code reappears as not present again.

TBH I can't remember much about live data except that I remember there was nothing reading with regards fuel pressure etc.

My main concern was that I had identified zero voltage on pins 1 and 2 of the fuel injection control unit, where TIS advises that 0.5...4v should have been present.

TIS does not detail which control module, i.e. the ECM or the fuel injection control module actually supplies the 0.5...4v, so at that point I was not able to establish if the ECM had a fault or the fuel injection control module?

I consulted Autodata pin data at that point and have made a decision whereby I think the fuel injection control module is faulty, this however is not based on sound evidence, but using the checking procedure and looking at pin data, which advises that the voltage supplied to/from the fuel injection control module and the ECM is a two way signal, and hence the fault code relating to the fuel injection control module as being faulty.

At that point neither the ECM or the fuel injection control module is sending or receiving a voltage signal and therefore could not conclude exactly which control unit actually is at fault, so I have sent the fuel injection control module away for test and repair if required, if they advise it is ok, then lesson learned, but if faulty then I guessed correctly.

I am not sure what more I could have done to guarantee the diagnosis?
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Re: Vauxhall Astra G

Postby Technician » Fri Jul 24, 2015 5:52 pm

The electronics company rang me today and said that they tested the fuel injection control module and found that the module was faulty, they have advised that they have now repaired it and charged me £225, they tell me that the module will be back with me next Tuesday, so based on current work load I should have the car up and running Wednesday next week.
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Re: Vauxhall Astra G

Postby Robski » Fri Jul 24, 2015 6:20 pm

I am not sure what more I could have done to guarantee the diagnosis?


I almost forgot, with the correct equipment you can read the pump controller for DTC's


TIS does not detail which control module, i.e. the ECM or the fuel injection control module actually supplies the 0.5...4v, so at that point I was not able to establish if the ECM had a fault or the fuel injection control module?

You could have determined that !
C-018 injection pump circuit, T015-T017 seems quite self explanatory to me.

I guessed

:shock:

TBH I can't remember much about live data

That's the second port of call after DTC's.

Are you a Pico owner or did you just post here for advice ?
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Re: Vauxhall Astra G

Postby Technician » Fri Jul 24, 2015 7:35 pm

I almost forgot, with the correct equipment you can read the pump controller for DTC's


I have TECH II, this read the codes.

TIS does not detail which control module, i.e. the ECM or the fuel injection control module actually supplies the 0.5...4v, so at that point I was not able to establish if the ECM had a fault or the fuel injection control module?


You could have determined that !
C-018 injection pump circuit, T015-T017 seems quite self explanatory to me.


Going back through TIS Checking procedure. T015 was OK, T016 had no voltage present, T017 also had no voltage present. T018 asked for a resistance > 500 kOhm, I recorded < @ 1065 Ohm

I guessed the fuel control unit at fault instead of the ECM, you may be shocked but


I'm not shocked, I followed TIS through and found conclusively that T016, T017 and T018 ALL told me the pump controller was faulty, but I had doubt in the area of which way the voltage passed from either the fuel controller to the ECM or the ECM to the fuel controller, please advise how I would know that?

TBH I can't remember much about live data

That's the second port of call after DTC's.

I have no problem with that but instead I followed through with TIS as explained above, the tests I did were direct at the pump controller and ECM, not through the 16 PIN data socket, surely you don't condemn me for checking direct at the components ?

Are you a Pico owner or did you just post here for advice ?


I have bought diagnostic accessories from Pico, very good stuff, but when I invested in my scope I was lead towards Snap On, however I have been looking at Pico scopes and this is my next investment.
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Re: Vauxhall Astra G

Postby Robski » Fri Jul 24, 2015 7:45 pm

I have bought diagnostic accessories from Pico, very good stuff, but when I invested in my scope I was lead towards Snap On, however I have been looking at Pico scopes and this is my next investment

I didn't mean it in that respect, just finding out if you're a scope owner. Otherwise it would be pointless advising scoping in any of your posts.
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Re: Vauxhall Astra G

Postby Technician » Fri Jul 24, 2015 7:48 pm

Sorry didn't know what you were getting at, but when the controller is sent back Tuesday I will be scoping and keeping a record of data for future use. Thanks for your replies.
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