I recently acquired a 2007 Golf, history unknown with a few issues (locks etc) and some that I didn’t notice pre purchase
I’m not at the end of my attempted diagnosis but I’ve reached a point where I’m running into things that I don’t know the correct behaviour for and therefore cannot trouble shoot.
I’m not able to afford VCDS so I’m borrowing my buddies Foxwell tool.
Symptoms:
‘Error’ flashes in odometer for a few minutes before displaying mileage
ABS light does not light up EVER.
ESP light does not light up EVER.
ABS and ESP do not function.
ABS/ESP system function test required;
So far all unsuccessful attempts to do the abs/esp function test... hard to find a space big enough to be sure I’m not just messing it up. After failed attempt the hazards flash and I have to clear code 01487 to get another go.
Codes: (current/after fixing/clearing other/unrelated)
ABS;
01486 system function test activated
Instrument Cluster;
00003 control module - sporadic 01 4 - defective
Fault status 01101110
Fault priority 2
Fault frequency 1
From here it’s a bit convoluted;
Possibly relevant things:
Old code on ABS ‘01542 yaw rate sensor G202 sporadic 01 4 defective’
On live date lateral and yaw seem to respond to the car moving but do seem ‘skitty’ is that expected? No errors thrown on this while driving or is that because there would be no errors until the system function test is complete?
When I got the car the tracking and steering sensor were way off, basic settings for steering angle sensor performed after tracking, steering assist range setting performed, all behaviour there has been fine since.
Diagnosis with live data:
Measuring blocks on various control modules;
All switches in car functioning/return activated/on as expected.
Steering angle sensor is good.
Brake pressure sensor is good.
At low speeds wheel speed sensors are good.(abs cuts comms above 30mph ish -is this normal/todo with system function test failing or another symptom?)
ABS warning light is flashing in live data but never on dash.
ESP/TCS warning light never seen to be active in live data.
Channel 206-1 of the Cluster show ‘error code ‘20’’.
CAN diagnostic measuring blocks on various modules showing possible errors related to the Brake electronics(ESP) like ‘electromagnetic compatibility’ and ‘can bus data status (power)’ where related MBs for engine/instruments/etc show a value of 0 the ‘brake electronics’ show 1.
ABS pump active test was all good.
Other general things,
Inspection of Cluster shows it has been removed in the past (suspicion of the abs led being tampered with?)
Car is very very clean inside (must remove seat to fully inspect ESP sensors, water!?)
ABS module soft coding was for the wrong engine, if VCDS wiki is correct(could this be a botched replacement? Part no ends in K)
Service reset problem probably not culprit for dash error.
Tmps(abs based seems to work normally).
I’m working my way through the wiring but am having trouble finding any good wiring diagrams to aid testing, any pointers?
It’s raining today so I’m hiding but plans include load testing, cleaning up all earths, physical inspection of all wires/plugs.
I was at one point hoping for just a fuse somewhere but no luck there,
If it is 1 or multiple modules where do I start? Bearing in mind I can barely feed myself, I can afford a second hand esp box or a can gateway but would rather not get unneeded bits if I can help it. For repair if the big ones are dead, £180+vat fixed for abs/esp or instrument Cluster is reasonable but I want to be so so very sure before sending either away.
Unknowns
Comm error from gateway or abs?
Error on dash because of dash or mil request from abs?
Abs sys function failing because of me or abs or esp or dash?
Abs comms drop out during live driving test normal/due to sys func/caused by something else?
Everything else on the car seems to work completely normally.
Cruise control, ps, Windows, mirrors, door locks, lights, auto lights, auto wipers, washers, heaters, speedo, tacho, all other startup/warning lights (apart from abs and esp lights) all possible active tests performed ok. No other fault codes.
Does this sound familiar to anyone? Can anyone describe the correct behaviour around the abs sys function test ie lights/codes/funkiness?
Any thoughts appreciated, thank you!