Reprogram ECU Required

[wullieb1]

2005 Astra AH 1.8L X18XE engine.

I think the ECU has gone tits up. Does replacing it require any reprogramming?

Symptoms are

Won't crank
All lights and electrics appear to be working as expected
When I turn the key to start I can hear the ECU relay in the fuse box click but nothing happens

If it does need reprogramming is there anyone in Brisbane, other than Holden, who can do this??

Cheers.

[guy 27]

if thats all you're going off I'd doubt it will be ecu as engine will still crank if ecu is dead.

where in brisbane are you?

[wullieb1]

Wakereley.

Yeah just seems really strange.

Tried the rocking back and forth for the starter motor to no effect.

Haven't really had a chance to get into it yet.

If its any help it just stopped at a set of lights and will not turn over. The ECU relay was clicking like mad when the ignition was turned on, disconnected the battery overnight and its stopped and clicks only when the key is turned fully to crank the engine.

All electrics appear to be fine and there are no lights on the dash nor were there when it cut out. Tried the pedal trick and nothing comes up on the dash.

Someone mentioned the Crank Sensor but surely that would throw an error rather than just stopping the engine from running.

[guy 27]

checked main fuse?
does starter motor even make at least one click?
is there power going to starter?

without seeing the car its hard for me to say exactly what this issue is.

[wullieb1]

checked main fuse?

Yes. All fuses are fine.



does starter motor even make at least one click?

No.


is there power going to starter?

Haven't checked yet. Will be doing that later.


without seeing the car its hard for me to say exactly what this issue is.

Thanks for the pointers mate. It is appreciated. Been a while since I've had to get into a car to check stuff lol.

[wullieb1]

Ok got home and decided to have a bash at this.

Re-connected the battery and tried to crank it again. Before i even get to the crank point i can hear the relay for the ECU clicking like mad.

Disconnected power and removed the relay. Turned the key on and when i actually turn the key fully to start the car i can hear a click.

Also noticed that the oil pressure light, spanner light and the EML light all flash.

Maybe time for an auto spark. Anyone have a recommendation for a mobile one and what sort of cost they are?

[gravy258]

is the battery OK ?
have you tried testing the starter by bridging it out ?
always best to try the simple things first.

[wullieb1]

is the battery OK ?

Appears to be. I had it connected to another car using jump leads yesterday and it was still the same.


have you tried testing the starter by bridging it out ?
always best to try the simple things first.

Trying to get a set of car ramps so i can get under the car.

[wullieb1]

Ok quick update.

Had some time to do some diagnostics on the car and found a couple of issues.

1. Seems there is an earthing issue. The minute i put a jump lead between the battery and the engine the ECU relay clicking stopped and the car would attempt to start.
2. Starter motor seems to be fubar. Removed it from the car and connected the battery directly to the solenoid and it pushes the cog out but spins it exceptionally slow. Connecting the battery directly to the positive on the starter motor spins it as it should be.

So it looks like i need to add a good earth to the engine, can anyone supply me with the earth connections so i can check them?, and a new starter motor.

Time to phone the scrappers tomorrow :) :) :)

[guy 27]

off the top of my head your main earth points in the engine bay should be.
1) slam panel to cylinder head
2) starter to battery
3) relay box to top passanger corner near strut tower
4) ecu to wiring harness
there are several more but those should be the main ones for the engine.

also shoot me a pm tomorrow. I've got a couple of starter motors here to suit z18xe

[SilentShout]

you can take the battery down to super cheap auto and they do a free battery test with a full print out.

I had the same issue in my S15 back in the day. Turns out the battery randomly dropped a cell on the negative terminal side which lead me to think it was an earthing issue.

From memory the ECU doesnt have a "relay" just a fuse, what your hearing might be the starter relay or the tick might be the solanoid on the starter triggering. (possibly the fuel pump relay too however it doesnt sound like a fuel issue here)

easiest thing to do is test the battery as its free and costs nothing then if that checks out go from there.

Gotta love cars

1 problem could be caused by 100 different things :facepalm2: