ECU Change = More Problems....Help Needed ASAP! *** Update/More Questions - Post 18, 12/1/11 ***

[Jim-Bob]

I've just fitted an unlocked single plug ECU to my VTS, went to fire it up today but once the battery was connected and i shut the boot the alarm went off which is to be expected, only the key fob wouldn't lock/unlock the car?

Is this because the ECU has been changed and the keyfob is no longer recognised?

Or is the central locking independent from the ECU and my keyfob battery is just dead (wasn't brilliant and hasn't been used in a while)?



This meant the alarm kept going off whenever i opened or shut a door so i bit the bullet and jumped in with the alarm screaming and tried to start the car as i thought this might cancel the alarm...

Engine just turned over but didn't try to fire, the immobiliser light isn't on so it wasn't that (immobiliser box has been removed), but in hindsight i guess you can't start the car with the alarm still activated/going off as that would allow you to jump in, hot wire it, deactivate the alarm but starting the car and drive off, which i guess it won't let you do?

Is my assumption correct?

Dash lights came on but flickered a bit, is this normal when try to start the car with the alarm going off?




Any help will be greatly appreciated as i'm desperate to get the car running again...


James

[ryanmt]

The alarm is separate from the ecu. Unless you have an aftermarket alarm, in which case all bets are off!

[jeffchiz]

your key fob shouldnt be affected by the ecu at all i have a unlocked vts ecu in my 16v vtr and my fob works fine, alarms though i have no idea always seam more hassle than they are worth lol

[blackie_2k5]

you should still be able to start the car with the alarm going off provided as said its not an aftermarket alarm/imob

[Krys_23]

Sounds a bit like the way my clifford used to react, if it is a clifford press the top and bottom buttons on the left at the same time which puts it in a different mode and is the only mode i can drive my car without the alarm going nuts!

[Jim-Bob]

It's a standard alarm, engine did turn over but wouldn't fire, however the cars not run for 8 months or so, so should I just keep trying it?

Would the dials lights dimming/flickering suggest a slightly flat battery?

James

[Krys_23]

Take your fuel line off and check for fuel first, fair chance you've just locked your unlocked ecu by the sounds of things.

[blackie_2k5]

could be, but if its turning over ok it should fire? Have you touched engine wiring? Could be a dodgey earth with dimming lights

[Jim-Bob]

Take your fuel line off and check for fuel first, fair chance you've just locked your unlocked ecu by the sounds of things.

Where's the best place to take the fuel line off?

How would the ECU of locked itself? There's no immobiliser plugged in?

could be, but if its turning over ok it should fire? Have you touched engine wiring? Could be a dodgey earth with dimming lights

I've changed the loom and power cables but I've checked it's all connected, how negative lead wasn't attached direct to metal, it was on painted metal which probably isn't ideal?


James

[Krys_23]

On the injector behind the inlet, pretty easy to take off, just pull it off and put the key to the second click until the fuel pump primes and see if fuel comes out.

[jeffchiz]

could be, but if its turning over ok it should fire? Have you touched engine wiring? Could be a dodgey earth with dimming lights

IF the ecu is locked somehow the engine will still turn over, i locked my unlocked ecu and it would turn over but not fire

[jeffchiz]

Where's the best place to take the fuel line off?

pull it off the fuel line

[blackie_2k5]

IF the ecu is locked somehow the engine will still turn over, i locked my unlocked ecu and it would turn over but not fire
i know mate, but i had a feelin this was after the loom change, dimming lights need diagnosing, but id assume if wiring is ok the ecu is locked as said, but get that neg wire sorted as it could also be or cause problems

[Liam_]

I would just unplug the alarm box for now (see my guide - unplug the connector).

Get some jump leads on it. If it doesn't fire, then check for fuel, spark etc.

[Jim-Bob]

I would just unplug the alarm box for now (see my guide - unplug the connector).

Get some jump leads on it. If it doesn't fire, then check for fuel, spark etc.

I guess that will shut the alarm up and allow me to try turning it over a few more times see if i can get some fuel through :y:

James

[Mochachino]

Check for a spark, less messy than checking fuel. If its cranking over but not firing then its locked, unless you have missed an earth out. If its turning over then check for fuel. If no fuel then probably an earth. If theres fuel aswell then :S

[Jim-Bob]

Check for a spark, less messy than checking fuel. If its cranking over but not firing then its locked, unless you have missed an earth out. If its turning over then check for fuel. If no fuel then probably an earth. If theres fuel aswell then :S

Do i just whip the coilpack off to check the spark?

I have the immobiliser, pick up ring and key for the ECU, but the immobilisers have different connectors so i can't fit it and check its unlocked :n:

Any ideas how i can splice single plug immobiliser into the 3 plug interior loom?

James

[Jim-Bob]

Right bit of an update...

As advised i removed the alarm box so that wouldn't go off this time so i hear what was going on...

Also filed away the paint around the stud i've got the negative battery lead attached to so i could rule out dodgy earth...


Then tried starting it:

First position on ignition - battery light only no other lights or noise (should i hear the fuel pump here?)

Second position - battery light, passenger airbag light (airbag turned off), ABS (for a few seconds then goes out) and handbrake light. High pitched whine coming from engine bay, three different pitches that alternate but all loud high pitched sounds which stay on continously

Third position - engine turns over but does not fire and dials bounce around a little, digital display show oil levels, high pitched noise disappears.



This noise seems to be the major problem, it was there prior to any loom/ECU change, but only after the three plug ECU locked itself...

Any ideas what this could be?

It is loud inside the car but is even louder when you open the bonnet and stick your head in the bay, seems to be loudest at the back of the bay...only thing i can think of that is electrical back there is the starter motor? But that seems to be working fine as its turning the engine over? Any ideas what could be causing the noise?


James

[ryanmt]

no ecu light on the dash is a bad sign. The ecu isnt even powering up for some reason.
Is the relay under the ecu clicking on and off?

[Sophia_Bush]

the loudness will be the relays and pump I'd imagine? Guess you checked spark and fuel right?

[Jim-Bob]

no ecu light on the dash is a bad sign. The ecu isnt even powering up for some reason.
Is the relay under the ecu clicking on and off?

Not been able to check as i was by myself again...it was something i was meant to change as i've got some spare ones upstairs...

the loudness will be the relays and pump I'd imagine? Guess you checked spark and fuel right?

Which relays Gav?

Not check spark or fuel yet as i've been by myself as i said above :n:

James

[jonez1992]

could it possibly be a crank position sensor?
that caused my dials to play up on my golf and some dodgy starting?, and they dont always chuck a code into the ecu?

[jeffchiz]

could it possibly be a crank position sensor?
that caused my dials to play up on my golf and some dodgy starting?, and they dont always chuck a code into the ecu?

this could possibly be it when my cps went it would turn over but not fire

[Jim-Bob]

could it possibly be a crank position sensor?
that caused my dials to play up on my golf and some dodgy starting?, and they dont always chuck a code into the ecu?

this could possibly be it when my cps went it would turn over but not fire

Is there any way of testing to see if this is at fault?

James

[jonez1992]

i would try unplugging it as this should put the ecu into default mode and see if it fires, if not may be worth checking resistance

[Krys_23]

Yeah take your coilpack off and rest the four plugs on your cam cover providing its the metal j4 one's, or any bare metal infact, turn the key and see if they are sparking, if not check the sensor is in correct and try again.

[jeffchiz]

Is there any way of testing to see if this is at fault?

James

well my sensor was shattered so when i pulled it out it was quite obvious lol but i dont see how it could be damaged if the car hasnt moved

[Jim-Bob]

i would try unplugging it as this should put the ecu into default mode and see if it fires, if not may be worth checking resistance

Cheers mate I'll give it ago, don't have a multimeter at home so testing the resistance isn't possible at the minute :(

Yeah take your coilpack off and rest the four plugs on your cam cover providing its the metal j4 one's, or any bare metal infact, turn the key and see if they are sparking, if not check the sensor is in correct and try again.

I've got JP4 covers so I'll have to dig out a sheet of metal to try that on, guess if I open the drivers door to reach the ignition I should be able to look in the bay at the same time?

well my sensor was shattered so when i pulled it out it was quite obvious lol but i dont see how it could be damaged if the car hasnt moved

That's what I'm thinking but I'll check anyway :y:

James

[Krys_23]

Best bet would be get a mate to turn the key while you check for spark pal, just hold the plugs on the chassis somewhere.

[jonez1992]

the only thing is it could have short circuited/ high resistance or something along them lines which wont show up when you take it out but may still cause problems =]