Doblo Immobiliser on after removing engine to change gearbox and sump.

[DaveB13]

Hi folks, newbie and first post. Hoping for some advice and guidance as struggling to get to the bottom of this issue.
I bought a doblo 1.4 8v mpv with a burst gearbox and various other mechanical issues. As gearbox was to be changed and new sump fitted, thought may as well take engine out and do timing belt, water pump, change clutch etc and replace grinding steering rack.
The engine was running and starting fine before but after putting engine back in car the immobiliser light is on and engine turns over but no start.
I have checked the following...
All earth's resistance 0.5-6 ohms
Found broken pin on ecu, I must have damaged some how, got new cloned ecu.
Bought multieuscan and all that came up was u1601 on the body computer, Can bus error.
Interestingly no software info or any other information apart from iso number shown.Attached pic. Also unable to connect to engine ecu.
Battery is good and fully charged and cannot see any broken wires near ecu or body computer.
Cleaned all contacts with contact cleaner spray.
Removed radio as suggested on other threads.
Tried both keys, diagnostic says keys read but no code from ecu. Changed ignition key reader just in case, no difference.
Went back today to recheck earth's same reading with ignition off but with ignition on resistance jumps to 1.5 ohms. Could this mean a faulty sensor somewhere or issue with body computer.
Any suggestions appreciated.
Thanks in advance.
Dave

 

[varesecrazy]

Hi Dave

Barring the ECU problem..

Bad earths tend to feature with this..

Set up a couple of jumplead cables as additional chassis to motor links.. just to rule it out

Revisit the random bits you disturbed in the swap too

 

[Communicator]

I think that communicating with the ECU is paramount. If the ECU and BCM cannot communicate, how are they going to interchange messages and allow the BCM, which has recognised your key, to unlock the ECU?

It is not possible to accurately measure earth resistance with a standard multimeter. The resistance of the connections will be a significant part of the reading, which will also be affected by any other current flowing in the circuit under test.
So at least do not worry about changes with ignition on.

 

[DaveB13]

Thanks for the replies so far. I will re-trace my connections disturbed when removing the engine and try jump leads to engine earth points.

 

[DaveB13]

OK folks, quick update.
I have re-checked all the earths, cleaned the body earth points again. Added an additional engine to body earth, tried jump leads and checked my starter connections. Still no change apart from one thing which I noticed before checking the earth's again. When I turn the ignition on now full beam comes on for a few seconds and then turns off.
Will start checking for broken wires next in the loom within the engine bay as these were the only other electrical items disturbed.
Any further thoughts appreciated.

Cheers

 

[varesecrazy]

Any closer to having the
ECU repair/ swap?

That headlight flash does sound odd...

Dont want to disturb too many more things ..yet..!!

 

[DaveB13]

Thinking the body computer as engine ecu is refurbishid/cloned. Also the fact that no software or programme data is showing when multieuscan plugged into body computer.
Certainly expanding my vehicle electrics knowledge.