V6 Engine will not crank over but will start if I bypass the starter relay.

[OlderVZDude]

Hello All
I have a 2004 VZ which will not crank over however if I remove the starter relay & short circuit the battery to the starter motor it will start & run. I can then stop & start the car with the relay for the rest of the day. If I do not restart the car for 3 or 4 hours then I have to bypass the relay again. The local Holden dealer wants to replace the Engine Control Module ($1,300.00).
I would appreciate any suggestions or experience regards this problem that I have.

Thanks
OlderVZDude

[db_notso]

does sound like a sticking switch

have you tried swapping the relay with another could be a worn relay not letting enough current through so you jump it and woolah!
then car is hot on restart requiring less current to signal starter

there are MICRO SWITCHES in the ecm that have control over the ignition circuits if these fail it wont crank
normally it wont crank at all

also try jump starting the car when it WONT start before you bridge it
sometimes low battery voltage (especially after long sitting time) can cause only certain circuits too malfunction

good luck

[OlderVZDude]

db_notso
Thank you for your thoughts.
I have tried both keys, replaced the relay, replaced the ECM fuse & NRMA have tried to jumper start the car.
I have Temporarily connected the relay & connected an earth to the ECM leg of the relay & it started fine.
The ECM appears to not be supplying an earth for the starter relay.

Still looking for the answer.

Regards
OlderVZDude

[db_notso]

this works then here is the diagram you need

so depending on which leg of the relay your connecting an earth too....
pin x1_86 is earthed inside the ecm PERMANANTLY so if no other fault i would just earth that wire
if it didnt cause engine light and all worked just earth it

from what youve described to me
x1_87
x1_30
x1_85
is good circuit all except x1_86

so if circuit between x1_86 (pin 86 on relay) and pin x2_35 (on ecu) is not open circuit or high resistance
and its an auto or if manual the clutch switch is operrating correctly (disengages cruise control? or get it checked with scantool)
then the fault is inside the ecm

http://forums.justcommodores.com.au/...connectors.png

theres the ecm connectors good luck man~!

[OlderVZDude]

Hello db_notso
Thank you for the diagrams.
I have proved continuity from relay leg quick connect socket (86) to pin x2-35 with a digital multimeter.
The car is an Auto & I have held the key to the start position & shuffled the shifter between park & neutral without success.
It was ECM leg (86) that I connected the earth from the battery to & the engine started.
I have also looked for an earth from the ECM at relay socket quick connect 86 with key to start position using the meter & did not get any earth.
I have noticed warnings like ESP failure, low fuel level,ABS failure & fuel guage error & service vehicle soon with the spanner symbol when I try to start engine initialy
& after bypassing the relay but are not present when I start the car with the relay after the initial bypass start.
I am interested in what the key start connects to within the ECM as this must activate something perhaps even supply the earth to the starter relay coil via leg 86.

Regards
OlderVZDude

[bigdaddycool]

Have someone fix/look at your ignition barrel, had this issue before. The problem lies at the bottom of it.

[db_notso]

yes thats correct this is all assuming you have a on/crank signal to pin x35_85 on the R1 igniton cont relay

check with a multimeter that when key is in run (or) crank position there is voltage supplied to that pin
also should be voltage at x2_31 on the ecu in crank position
x2_31 this one is the signal to ecu that key is in crank position then the ecm internally earths the starter relay signal side that you have been earthing out manually

if either of these fail then fault is in the ignition switch on the end of the ignition barrel (left side under steering coloumn covers)
they stick and then fail to provide a sgnal to the ecu they also get brittle with age

if the signal to these towo pins is good it needs an ecm module

hope this helps ...

[papj]

i'm interested in how you got on with your problem as i'm haveing the same problem with my ute in every detail

[db_notso]

well now if you read above hes got it narrowed down to either an ecu OR ignition switch
the switch is more likely though

[OlderVZDude]

Hello db-notso & bigdaddy cool,
Thank you both for your suggestions, I have had the opportunity to test some of them.
When I turned the key to the ON position, I felt the engine control relay operate.
Disconnected the x2 ECM connector from the ECM & used a pin & multimeter to measure 12v successfully at x2-24 which is permanently supplied via the engine fuse to the engine control relay coil & leaves on relay leg (86) looking for an earth from the ECM to operate the relay.
I then used the pin & multimeter at x2-31 to look for 12v being supplied from the key in the START position & watched it the go from 0v up to 12v when I turned the key to & from START position.
Lastly I reconnected the x2 ECM connector & set the multimeter for continuity & looked for the earth at starter relay leg socket (86) which should have supplied the earth from the ECM to for the starter relay coil when I turned the key to START but I did not get the earth.
Based on these tests I believe that the key barrel switches are O.K. & the ECM is not able to supply the earth to allow the starter relay coil to power up & therefore not operate the relay to pass power to the starter motor.
I think the ECM needs to be replaced.
Hi papj , I hope the information supplied by db_notso & bigdaddycool is as helpful to you as it has been to me & maybe there is some benefit to you from what I have done.
I look forward to any further thoughts before I book it in at the dealership.
Regards
OlderVZDude

[jetboy]

subscribing to this thread

[db_notso]

no probs man the testing for this circuit is easy once you have your head around it

i after reading your testing think you need to get a new ecm
and it will need to programmed (always have to send mine to holden to do it, its a pain but they havent stuffed one up yet)

[OlderVZDude]

Hello all,
db_not so , you mentioned that the ECM would have to be programmed.
I imagined that the ECM would be a bolt on & plug on the connectors type device that I could replace myself & that each ECM would be manufactured to suite
the appropriate level of car and engine that you have – so much for that idea.
I now understand the labour cost if the ECM has to be programmed before or after being fitted onto the car.
Could someone explain as to why it needs programming, perhaps the ECM is a one size fits all device & it is programmed to match the level of car & engine.
In any case I will now book it in with the dealership for next week after learning that this programming is required.
Regards
OlderVZDude

[db_notso]

normally an ecu is reset
tehn removed
then new one in
then new one programmed (latest software and vin imprinted in programming)

there is an ecm for different models and makes i think vz and ve are VERY similar though
but still took them about an hour to do the one i took to them with a similar fault as i had to wait then return to work (was 3rd year still!)
but the fuel gauge didnt work either and said service vehicle soon with no codes in ecm or ipc except ignition circuit
hence all my drama working it out then!~

[db_notso]

sorry peoples but due to the wirning diagram being able to be used to nick a car im deleting it
beofre some yokel nicks our vz's!~

[OlderVZDude]

Hello again,
I appreciate the assistance received on this forum especially from db_notso.
I appreciate & understand your thoughts about the circuit.
Although I have not been able to fix my problem & do not know what caused it, at least
know that the dealership is on the ball.
I now have an appreciation for what I am getting for my money.
There is a Gregorys Manual (273) available for the VZ which covers VT, VX, VY & VZ.
I hope this forum helps others as much as it has helped me.
Regards
OlderVZ Dude

[db_notso]

thanks man the internal switches can break just due to time and the heat up cool down repeated cycle of engine use
which is more understandable on these thanks to position of the ecu
good luck let us know if ecu does fix her up for ya!~ ( which im sure it will if all tests said were done)

[OlderVZDude]

Hello all,
I am sorry that I have not updated you with my VZ story as we have been away on holidays.
Well the VZ has had a successful brain transplant.
Unfortunately the faulty ECM was not left in the boot as requested so that I could cut it open with a hack saw.
By the time my wife picked up the car & I realised that it was not in the boot the dealer had disposed of it.
Fortunately for us & our holiday it never missed a beat while we were away.
The cost was worth it in the end although it knocked a hole in the holiday money but we had to have it done for the holidays.
It is good to have the car starting when & where you want it to.
Regards
OlderVZDude

[Shorty33]

my VZ developed the same problem after being unused for six weeks.
A friend is in a similar situation.
Going through the archives of this Forum, the problem seems common.
My question for OlderVZDude is -
how much did the replacement & reprogramming, and any other necessary steps, cost ?

thanks in anticipation.

[OlderVZDude]

Hello Shorty 33,
I was initially told $1,300.00 but after some delays on their behalf I got the price down to 1,100 for the supply, fitting & programming.
Sorry about not responding early been away with work.
I hope it has worked out well for you.
Regards
OlderVZDude.