REC crashed? Certainly seems that way

[Ian T]

Here's an interesting one. A local garage over in Croydon asked me to go down and take a look at a customer's car yesterday that they couldn't fix, which I did.

Mk5 Astra 1.6 Twinport, 2006 '55 plate.

The problem was reported as no central locking, but as with these things, it seems there's always a cause. It started out with no cigarette lighter and after the owner pulled several fuses trying to find a duff one, the cigarette lighter was fixed but central locking was completely dead. Unusually the car also has check control (on an 'Active' model) and that was exporting parking light failures.

Plugged Tech2 in and attempted to navigate straight to the C/L module - "Mandatory Module not present" so I went back to the top and ran the vehicle modules presence check, which failed to find anything on the slow speed CAN bus. Started following the checks in TIS but realising they were checking basic things like power to the modules, I unplugged the REC to see if any of the other modules returned into the list, which they did, full of DTCs. Plugged the REC back in and it returned also. Reset all the codes (lots and lots of them all over the vehicle) and was left with just two relating to the C/L lock signal and unlock signal.

Actuated the locking via Tech2 to make it lock and unlock (logic was to set all the motors to the same position) and then was able to reset the remaining ccdes.

It looks like whatever was done really upset the REC, which then locked up the low speed CAN bus.

Interestingly I could see that the remote control worked via Tech2 in another data list outside the REC (might have been CIM).

The car now seems fine, but has anyone send this before?

Ian.

[pecky]

Hi Ian,

Could well be a faulty REC, could also indicate a canbus fault.

I've had them where the terminal in the diagnostic port was in poor condition and wouldn't let me connect, so it's always worth looking there.

I can't remember the diagnostic route on the low speed CAN, I know when putting my bench loom together, depending on how I wired the REC, I would also get other modules dropping out, so I guess wiring or the REC could cause what you have found.

[domtorredo]

Had on vectra, failed when programming sometimes not present, turned out fault in cim, to finish programming was heating up Motorola IC than was ok (common fault on early vectra)

[Ian T]

Thanks guys, the car hasn't come back so it seems to have been a one off.

The beginning of the story was apparently a failure of the cigarette lighter fuse, the owner's subsequent fuse pulling seems to have confused the REC. I haven't looked at the REC to understand what components it has but it was certainly behaving as though it was executing NOPs. ;-)

Hopefully no harm done - moral of the story is disconnect the battery and reconnect before condemning anything.

Ian.