VP Check Engine Light Illuminated after fault reset

[plains203]

Hi All,

I have picked a heap of tips from this site so far, thanks to everyone for your great info.

I am having trouble with a VP commodore. When I turn the key to ON or start the car, the check engine light will illuminate. I removed the Engine Fusible link and then then later disconnected the battery and as soon as I turn the key to on (there is an immobiliser so I have to press the button on the remote) then the check engine light turns on again oh the electric fan also kicks in. When the car is running the aircon won't turn on when the check engine light is illuminated (this may possibly also work when the light is on I don't recall), as soon as the Check Engine Light goes out the aircon starts working (if it is supposed to). Also when the check engine light is not on when the ignition is switched to on then the fan turns off again. I have made a ALDL cable to suit the car and connected it. When the check engine light is on the cable will not function. If the check engine light goes out (which it sometimes does) the cable will stream data into WINALDL. No fault codes are displayed though. So I am hitting my head against a brick wall here, what should I be checking? It seems to me like the ECU is running in ALDL Bridge mode but without the flashing Check Engine Light, also using a 10K 1/4W resistor to bridge the ALDL plug doesn't change the Check Engine light condition. The car sometimes stalls when the check engine light is on and I am moving, or it may lose power. I was noticing it especially when the aircon kicked in but that issue seems to have changed. Any help would be greatly appreciated. Thanks all.

[delcowizzid]

sounds like the memcal isnt making contact in the ecu properly that makes the fan and engine light come on straight away it may have a new chip soldered in the memcal and its not soldered in properly

[plains203]

I pulled out the ECU tonight and disassembled it, I removed the memcal but didn't disassemble the memcal and reconnected it. I haven't reconnected the ECU yet, I will a little later in the morning. The memcal is stock.

[delcowizzid]

has the chip in the memcal still got a little silver sticker in the middle of it with 4 letters and 4 numbers on it.was the memcal clipped right in properly.could maybe be a dead ecu otherwise.

[plains203]

I will have to check for a sticker again. I put the ecu back in this morning after having the battery and ecu disconnected all night. Turned the key and the check engine light lit up. The memcal is quite secure. How can I be sure if the ECU is faulty? I have noticed that the ECU PCB is uneven in its thickness but I think it has some protective coating on it so that may explain that.

[plains203]

Ok pulled it out again. The memcal has a silver sticker on it that says Delco BABR 3575

[delcowizzid]

the light will come on before the engine starts.did your fans come on this time.thats a stock 91 vp chip .

[plains203]

Yes the fan did and I also started the engine and had the light on.

[delcowizzid]

find an ecu to borrow to test if its the ecu most likely is.

[plains203]

Ok I guess I will have to purchase a 2nd hand one due to not knowing anyone with a similar car.

Thanks for your assistance

[Zuicider]

where are you located? maybe a member in your area could help out

[plains203]

Country SA near Mallala

[plains203]

Anyone got a good suggestion of where to buy a well priced 2nd Hand ECU in Adelaide? City Dismantlers quoted $88 with a memcal (they don't sell seperately).

Thanks

Edit:

I can get one from Just Commodore Spares at Thebarton for $71.50 with a memcal and 3 Monthes warranty.

[plains203]

Just got home and swapped the ECU and it now works perfectly! Thanks heaps to all who helped (Delcowizzid). Tommorow I will change the memcal's and test again. I think my existing memcal should be better than the replacement the old one being the BABR 3575 and the new one being the AWUY 9398. Anyhow I will have a better idea tommorow! Now to fix the fuel gauge, change the tail lights and repair the indicator

[delcowizzid]

nice one yes try your other memcal both are for 91 but your memcal is a later release so ide stick with it.

[plains203]

nice one yes try your other memcal both are for 91 but your memcal is a later release so ide stick with it.