Golf mk5 1.9tdi BKC No glow plug light no Start

[JIMMYQ]

Hi guys got a mk5 golf 1.9tdi the chap said the glow plug light was intermittent he had to turn the key on and off a few times to get the light on then it would start.

Now there is no light on and no comms with the ecu so wont start ive checked all fuses and the relays everything seems ok took the ecu out and opened it outer case is corroded heated over everything put it back in still nowt.

I managed to get the glow plug light on once and it started im putting it down to the ecu and before I buy another one just wanted to ask if anyone has come across a similar problem?

thanks

[aidyk]

most likely under bonnet fusebox or at least ya can do a wee mod in fusebox to power up ecu I've did a few on golf 5 BKC golf and mk2 Octavia to overcome this problem in past. tomo I can give ya more info. just into bed now..

[JIMMYQ]

hi I took the fuse box apart seemed ok no corrosion or water ingress. if you can let me know mate cheers would save me some money and time :) thanks much appreciated

[aidyk]

hi I took the fuse box apart seemed ok no corrosion or water ingress. if you can let me know mate cheers would save me some money and time :) thanks much appreciated
I'll check in morning and reply when I get back from mot .
good night [emoji17]

[sjc1]

check the relay that sends power to the ecu and associated components i forgot what number vw call it. iv had a few where the contacts ware out and cause no comms and no glow light on the dash

[JIMMYQ]

all relays are fine checked them all under bonnet and inside the car

[doktorabg]

all relays are fine checked them all under bonnet and inside the car

Check Ignition Switch,I had a similar Problem with Audi A3 2007

[WOODWARD395]

JIMMYQ I know this seems totally wrong but check the brake light switch at the pedal and if your brake lights are working or intermittent I had a anther golf mk5 with a similar problem VW could not sort it took it to many garages having many problems with the dash and glow plug light and intermittently would not start in the end all went dead.
I was at a scrap yard with a friend about parts for his car was talking about my car this old boy was listening to my symptom's he just perked up and told me to change the brake pedal switch as he said it caused my problem.

I never really believed him but changed it and hey presto all my problems went away. still don't know how this caused my problems.!

[chriskross]

Problem is engine ecu, mpc bad contact.

try to heat up mpc, or reball it.

common problem on edc 16.

[WOODWARD395]

:suspicion: hard job re-balling every time I have tried it I messed it up there are places that do it with the proper oven but it costs.

but it pays to read the thread instead of skipping through it.:withstupid:

[autocargo]

Sometime re-flow gives good results. I've done one and still working so far...

[audivwauto]

replace the ecu

[audirules]

As Chriscross says the reball the MPC and your problems will be sorted out. This a common issue with edc16u1 ecu's which loose contact.

[alessioblaupunkt]

@WOODWARD395
Because in 1900TDI the rule is:
signal failure from brake light switch ---> the engine control unit reduces
the fuel quantity. Engine performance drops.

One question now: WHY??? If I test CLUTCH switch they are all open pressed or not!!
Tested a lot of car with 10 or more yrs no one is good!!
Pay attention a fail in the clutch switch will cause no problem.

[ACDC]

I'd get a wiring diagram if I were you, and start checking power supply and gnd points on the ECU connector BEFORE replacing, reballing or even touching anything. Might save you and the owner from getting a headache later ;)