You can't just replace the ECU and then start up the car. Your replacement ECU's VIN number does not match your vehicle's... You need someone to program your VIN number into the the ECU, read the security PIN code from your immobiliser and synch it with the replacement ECU.
Not for a Corsa B. I've replaced an ECU on a Corsa B. You only need the ECU, the barrel sensor and the transponder chip in the key. You plug the old one out, plug the new in and it starts.
Thanks for all the response.
1. originally, the check engine light never went off and the temperature sensor did not register.
2. I immediately replaced the crank sensor, that did not help.
3. no pulse to the coil coupled with the above made me decide to pay R380 to have the ecu tested.
4. They came back and said it is faulty, not repairable, and they failed to find me a replacement.
5. I managed to find a ecu set from Rand Scrapyard, paid R3000.
6 installed ecu, ignition, barrel, transponder unit, with the key that came with the set. Car cranks but no start.
7 Battery is good but does not start even when i jump it.
8 I am quoted almost R2000 to have the ecu dignosed and repaired by a better place than the first bunch that tested the original ecu and was so unhelpful.
9. Locksmith tells me key coding wont solve this problem. he feels this ecu is also shot.
10 I have checked that there is power and earth to the ecu.
11 I tried obd reader, Autel maxidiag md808 but it does not communicate with this ecu. It does not list the 1.4NE engine.
12 I understand the opcom scan tools read the corsas but I could not find anyone yet that has one.
13 I am willing to pay somebody to come and run dignostics to try and pinpoint whether the ecu is bad or i need key coding.
14 Does anybody maybe have a wiring diagram for me? I would like to trace the wires from the transponder unit and check that that has power.
15 maybe run an extra earth wire from the ecu to the engine and the battery?
Thanks in advance
So pro-tip, your original ECU probably wasn't shot.
Those ECUs are super hard to fry.
I was also told my Corsa B's ECU was broken back in the day, then replaced it and nothing changed.
In the end my wiring harness was broken but frankly, none of the "mechanics" had the skills to diagnose the problem.
They were mechanically focused and electronics was "confusing" and hard to understand for them.
Corsa B has a super simple ECU. The ECU operates on the speed density method and thus needs a working crank angle sensor, air temperature sensor, manifold absolute pressure sensor and throttle position sensor, at the very least. It can start without some of those sensor in certain combinations (except the crank angle sensor), but if you want the engine to run somewhat reliable you need at the very least those sensors. Without an engine coolant temperature sensor, cold start will be rough, but it will start.
How did this all begin?
Was the car working before?
And then how did it stop working?
These questions will make it easier to figure out how things went wrong.
But frankly you need a oscilliscope and look at the crank angle sensor output, make sure it is getting to the ECU.
Then look at the ECU outputs to see that they are firing.
If they aren't then I'd be willing to say, ok, maybe it is the ECU or the immobilizer but until that point people are just trying to replace parts and hope it works out.
