signs of a broken UCH??

[Fred@BTM]

car not cranking over

starter works fine if you bypass the control boxes etc etc, relays are all new etc

only £138 for a new one which ain't too bad! but obviously if that's not the problem then its £138 wasted!

 

[bmh.01]

Needs coding too obviously but i'm assuming your kitted up for that. Assuming the immobilser dearms? Does the uch close the starter relay?

Could try shorting the relay out and seeing if it'll crank on the key or is this what you've already tried?

 

[Fred@BTM]

yeah immobiliser disarms, if you bypass the relay it cranks, no fuel pressure either, ie the pump is doing f**k all, but that has a seperate relay which i'm going to change IF it stops raining!!!

there's some sort of secondary fuel pump relay output from the UCH

but i would've thought if the UCH was knackered nothing would work, ie lights, wipers etc etc

 

[Has]

yeah immobiliser disarms, if you bypass the relay it cranks, no fuel pressure either, ie the pump is doing f**k all, but that has a seperate relay which i'm going to change IF it stops raining!!!

there's some sort of secondary fuel pump relay output from the UCH

but i would've thought if the UCH was knackered nothing would work, ie lights, wipers etc etc

UCH can fail in many stupid ways.

Mine was replaced in Nov.
Came back to the car and full beam was stuck on as soon as you turned the car on!

Everything else worked fine.

UCH has known to fail in many ways, lights stop working, wipers go mad, windows go up and down etc..

 

[Fred@BTM]

just odd as the car hasn't moved, no battery hooked up or anything (V6 btw)

 

[Has]

just odd as the car hasn't moved, no battery hooked up or anything (V6 btw)

Does seem very odd.

double checked all loom components are plugged in etc?
im assuming uve been over it all tbh.

worth checking the relays for dodgy fittings, seen a few of them.

 

[Fred@BTM]

yeah i'm going to replace the fuel pump relay and the computer locking relay and try again

it did crank over on the key with the old engine loom (still no fuel pump), i've swapped the engine loom for one out of a smashed car (undamaged, old one had been chopped into)

and now it doesn't crank and no fuel pressure!

f**king french!

 

[Ads_172]

My UCH recently gave up and my main problems (all intermittent to differing degrees...) were:

Clicking from dash
Anti-hijack light flashing and arming / disarming itself
Windows juddering up and down / stopping working
Front wipers stop working
Rear wiper juddering
Indicators intermittent
Occasionally not starting at all - mroe often than not when I turned the car of and tried to restart to get the wipers working again

All sorted with the new UCH!

 

[bmh.01]

Any power at the coil pack(s)? As i'm sure the pump and coil is fed from the same relay, although the diagrams i've got don't cover the V6 so it may be different. Although the 1.4 and 1.6 use the same relay and just link it for each coil.

edit: The injector lock and fuel pump relay are closed by the ecu not the uch just noticed so may not be relevant actually. Fuel pump relay does power the pump and coils though, injector lock does the injectors and a few other things.

Could be looking towards the UCH if its not telling the ecu to unlock and close those relays?

 

[bmh.01]

Or damage on the canbus wires between the two?