FIXED - C2 ABS ESC Speedo problem (U0122, P0501)

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amallaburn
Posts: 23
Joined: 04 Feb 2021, 17:01
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Re: C2 ABS ESC SPEEDO problem (U0122, P0501)

Post by amallaburn »

I'll find out today for you (friends car)

I just went to site and followed categories that are displayed in the URL you sent

Seems to work if you right click and copy link then open new tab, paste and go

My Diagbox thing arrived, absolute b*ll ache of a software but set up a few virtual windows xp's using VMWare and gave up with updates just left at version 7.0.2 tried it with my Citroen Berlingo which I use for work and seemed to work completely fine, so will use this on the C2 to see what the Global test throws up

I'll check battery/alternator etc with multimeter first though

Should hopefully get to look at it today or tomorrow

Thank you for help so far

ozvtr
Posts: 33
Joined: 13 Oct 2020, 01:11
x 2

Re: C2 ABS ESC SPEEDO problem (U0122, P0501)

Post by ozvtr »

amallaburn wrote:
12 Feb 2021, 07:47
My Diagbox thing arrived, absolute b*ll ache of a software but set up a few virtual windows xp's using VMWare and gave up with updates just left at version 7.0.2 tried it with my Citroen Berlingo which I use for work and seemed to work completely fine, so will use this on the C2 to see what the Global test throws up
Excellent! Yes it's pain to install the software however the LEXIA gives you access to a lot more parameters and the descriptions of faults are far less ambiguous. Almost indispensable...no...indispensable!
I have found that for any individual line of PSA cars there are very few LEXIA updates. Meaning, if you have access to all the parameters you need (now), updates to the LEXIA software wont give you anything more. All of the current ECU updates require you to go online, which you cant do. However there may be earlier revisions of the software that contain the ECU updates for earlier cars. I don't know, maybe some one will say.
amallaburn wrote:
12 Feb 2021, 07:47
I'll check battery/alternator etc with multimeter first though
Good, that should eliminate the power/charging circuit. If it's not that it only leaves the battery. As I said in the blurb it's too hard DIYers too check batteries (now that its not possible the check the electrolyte any more).

Good luck.

amallaburn
Posts: 23
Joined: 04 Feb 2021, 17:01
x 2

Re: C2 ABS ESC SPEEDO problem (U0122, P0501)

Post by amallaburn »

My friend explained throttle to me today:

He said usually when he revs to say 4000 for example, it will return down quickly but at the moment when the fault is in it will stick high for a bit then slowly drop rpm.

Checked today:

Tested at 0 degrees Centigrade
Battery Voltage (CAR OFF): 12.3
[This battery has been in car one year]
Battery Voltage (CAR ON): 14.38
PD between Positive post and Positive connection: 0
PD between Negative post and Negative connection: 0

Got my Diagbox plugged in today.
Did a Global Test.
Have attached Screenshots with captions.
Global Test
Global Test
ECU
ECU
Injection Faults (Is Decat)
Injection Faults (Is Decat)
4.png
Power Steering ECU
Power Steering ECU
Power Steering
Power Steering
Instrument cluster test
Instrument cluster test
?
?

ozvtr
Posts: 33
Joined: 13 Oct 2020, 01:11
x 2

Re: C2 ABS ESC SPEEDO problem (U0122, P0501)

Post by ozvtr »

Ok first up looks like there is an after market radio fitted.

Go into LEXIA and 'remove' the radio altogether. That should fix the radio error and the multi function screen error. Go into the BSI (in LEXIA) to remove radio references.

Check the brake fluid level. Top it up to the 'full' level if it isn't already.

Most ECUs are whinging because they aren't getting speed information.

Catalytic converter gone. Is it OEM or after market?

Two of the other engine ECU faults appear to be physical faults? The throttle peddle, and 'brake light' switch are wired directly to the engine ECU. I'm not sure what the 'wake up' fault is about.
There are two sets of switches in the brake lamp switch. 1 set is used for the actual brake lamps and the second set is used for the engine ECU to tell if you are braking and ECU changes modes. It's also used by the engine ECU if you have cruise control. If you push on the brake it drops the cruise control out. The throttle peddles are almost bullet proof. I would look at the engine ECU electrical connectors for both of those faults. HOWEVER, the stop light switches can be dicky. The switch can be pulled apart and the contacts cleaned.

HOWEVER, THERE ARE NO ABS ECU FAULTS!!! What?!

HMM, problem; no speed info but the ABS ECU is OK?
Last edited by ozvtr on 12 Feb 2021, 21:00, edited 1 time in total.

amallaburn
Posts: 23
Joined: 04 Feb 2021, 17:01
x 2

Re: C2 ABS ESC SPEEDO problem (U0122, P0501)

Post by amallaburn »

ozvtr wrote:
12 Feb 2021, 20:28
Ok first up looks like there is an after market radio fitted.

Go into LEXIA and 'remove' the radio altogether. That should fix the radio error and the multi function screen error. Go into the BSI (in LEXIA) to remove radio references.

Check the brake fluid level. Top it up to the 'full' level if it isn't already.
Will do this tomorrow
ozvtr wrote:
12 Feb 2021, 20:28
Most ECUs are whinging because they aren't getting speed information.
Have finally found my jack, so can jack up front left wheel to get to ABS module tomorrow, then each wheel to double check sensors
ozvtr wrote:
12 Feb 2021, 20:28
Catalytic converter gone. Is it OEM or after market?
Catalytic converter removed, he's got one of those really loud exhausts straight through? or something like that
ozvtr wrote:
12 Feb 2021, 20:28
The other three engine ECU faults appear to be communications faults? Very strange. The ABS ECU might be corrupting the CAN BUS info from the engine ECU after all?

HOWEVER, THERE ARE NO ABS ECU FAULTS!!! What?!
I found this weird, I had to do Global Test a couple times as was exploring the software which crashed when I clicked check battery voltage, a couple times when I ran the test there was no Dialogue with ABS

ozvtr
Posts: 33
Joined: 13 Oct 2020, 01:11
x 2

Re: C2 ABS ESC SPEEDO problem (U0122, P0501)

Post by ozvtr »

Sorry, I had a thought about the throttle and brake switch errors and edited my post.

Ok. Then the ABS ECU is still on the suspects list. Does the speed info on the dash come and go or permanently stay off?

ozvtr
Posts: 33
Joined: 13 Oct 2020, 01:11
x 2

Re: C2 ABS ESC SPEEDO problem (U0122, P0501)

Post by ozvtr »

amallaburn wrote:
12 Feb 2021, 20:55

Catalytic converter removed, he's got one of those really loud exhausts straight through? or something like that
He will need to 'sleeve' the down stream O2 sensor or he will continue to get an engine light.

amallaburn
Posts: 23
Joined: 04 Feb 2021, 17:01
x 2

Re: C2 ABS ESC SPEEDO problem (U0122, P0501)

Post by amallaburn »

ozvtr wrote:
12 Feb 2021, 21:06
Sorry, I had a thought about the throttle and brake switch errors and edited my post.

Ok. Then the ABS ECU is still on the suspects list. Does the speed info on the dash come and go or permanently stay off?
It comes and goes

Will post info I get after probing ABS ECU connector tomorrow to try rule some things out

ozvtr
Posts: 33
Joined: 13 Oct 2020, 01:11
x 2

Re: C2 ABS ESC SPEEDO problem (U0122, P0501)

Post by ozvtr »

amallaburn wrote:
12 Feb 2021, 22:14
It comes and goes
Ah, intermittent. Like most of the other failures.

Maybe you were right! Check pins 12 & 13. It still might be a CAN BUS failure.

ozvtr
Posts: 33
Joined: 13 Oct 2020, 01:11
x 2

Re: C2 ABS ESC SPEEDO problem (U0122, P0501)

Post by ozvtr »

amallaburn wrote:
12 Feb 2021, 19:48
Tested at 0 degrees Centigrade
LOL! 35'C in my house today. Brisbane Australia. :rofl2:
amallaburn wrote:
12 Feb 2021, 19:48
Battery Voltage (CAR OFF): 12.3
[This battery has been in car one year]
Battery Voltage (CAR ON): 14.38
PD between Positive post and Positive connection: 0
PD between Negative post and Negative connection: 0
Hmm, alternator and charging circuit looking OK so far.

ozvtr
Posts: 33
Joined: 13 Oct 2020, 01:11
x 2

Re: C2 ABS ESC SPEEDO problem (U0122, P0501)

Post by ozvtr »

amallaburn wrote:
10 Feb 2021, 17:39
When turning steering while stationary the faults come up dash
Image
Might not be battery after suspecting the CAN BUS. I can explain all the warning lights except the air bag. Air bag an existing fault? Only pops up with the others? Still, only when stationary? Sounds like power supply.

With the ABS/ESP unit so close to the nearside front wheel, is it possible the moving of the wheel is causing a failure by touching something?

amallaburn
Posts: 23
Joined: 04 Feb 2021, 17:01
x 2

Re: C2 ABS ESC SPEEDO problem (U0122, P0501)

Post by amallaburn »

ozvtr wrote:
13 Feb 2021, 04:09
Might not be battery after suspecting the CAN BUS. I can explain all the warning lights except the air bag. Air bag an existing fault? Only pops up with the others? Still, only when stationary? Sounds like power supply.

With the ABS/ESP unit so close to the nearside front wheel, is it possible the moving of the wheel is causing a failure by touching something?
It does when moving also, apparently when braking faults can pop up, but can replicate fault by turning wheels while stationary
ozvtr wrote:
13 Feb 2021, 03:42
Ah, intermittent. Like most of the other failures.

Maybe you were right! Check pins 12 & 13. It still might be a CAN BUS failure.
When checking these is what is best Ground point to attach multimeter so I can reference voltage of pins to something?

My vehicle knowledge until last week extended to just car audio

Have also realised I never checked MAXI Fuses when doing initial checks on car so will have to do that today

wheeler
Posts: 4659
Joined: 21 Sep 2002, 19:07
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Re: C2 ABS ESC SPEEDO problem (U0122, P0501)

Post by wheeler »

You wont get a better ground that straight on the battery negative terminal.
To check the CAN lines measure the the resistance across pins 12 & 13 then 11 & 14 with the ABS plug disconnected you should get 120 ohms on each pair.
If you have good battery voltage on pins 1 & 32, an ignition feed on pin 8 & good earths on pins 16 & 47 and the CAN lines are good id say you have a dead ABS ecu.

amallaburn
Posts: 23
Joined: 04 Feb 2021, 17:01
x 2

Re: C2 ABS ESC SPEEDO problem (U0122, P0501)

Post by amallaburn »

Think I've got the problem, brown connector on PSF1 (28 WAY) BACK MIDDLE OF FUSE BOARD

Water ingress pin 19 snapped

All other connectors are fine, how to I separate top layer of fuseboard

Will upload all other pics and stats later

amallaburn
Posts: 23
Joined: 04 Feb 2021, 17:01
x 2

Fault found (maybe)

Post by amallaburn »

Had a look at everything today here are the results

Took ages to get connector off ABS, found an easy way to just pull little yellow tabs at the bottom with pliers
ABS -ESP Connector clamped
ABS -ESP Connector clamped
Clamped to side of car to make it easier when probing.

Battery before starting 12.42 V

ESP 7800 (ABS module)
with reference to Ground (Battery Negative):
Pin 1 (connects to PSF1 Black 8-way PIN 3): 12.42V
Pin 32 (connects to PSF1 Black 8-way PIN 2): 12.42V

Pin 12 (Intersystem Can Bus HIGH) to Pin 13 (Intersystem Can Bus LOW): 121.7 Ohms
Pin 11 ( Intersystem 2 Can Bus HIGH) to Pin 14 ( Intersystem 2 Can Bus LOW): 121.8 Ohms

I could not figure out how to take the ABS sensor off wheel to check, it seemed pretty stuck on there after undoing bolt. (FRONT LEFT)

Tried to check resistance on Pins of ABS/ESP connector for each sensor, just read 0 Ohms, tried measuring AC voltage while spinning FRONT LEFT wheel hub, read a little <1V but gave up on doing that and decided to test other things since voltages on 1 and 32 seemed ok.

The socket side of connector seemed completely fine, no corrosion, can just see grease in image:
ABS Connector socket
ABS Connector socket
Thought I'd start at top of list of pins
Pin 1 (connects to PSF1 Black 8-way PIN 3) Already checked, working

Pin 8 (connects to PSF1 Brown 28-way PIN 19):

Opened up this connector and voila problem found:
28 Way Brown Connector on PSF 1
28 Way Brown Connector on PSF 1
I opened other connectors on this board and all the rest were ok (couldn't get the front most grey one out though!) completely dry

Put my little magnifying glass on to find where Pin 19 was supposed to be, was not there because it was floating in the little water inside the connector, some of the pins were very brittle and loose and had a blue substance on some of them.

Couldn't figure out how to look inside this board so unsure if any damage underneath.

I used cotton buds/swabs/Q-tip (if you're American) to clean up inside and some WD40 Specialist contact cleaner (which I've used on my Xone 92 DJ mixer, so should be fine for a car connector), found that quite a few of the pins were brittle and moving about lots when cleaning.

Put everything back together, ran Lexia again and same faults appeared so no new faults.

Have found the lights on dash were permanently on rather than intermittingly


So.........
  • Can this connector be replaced ?
    What is the part number for this connector?
    Does somebody have wiring diagram for the 28 Way Brown connector, I would like to see what else uses this
IMG_20210213_145509.jpg
IMG_20210213_150956.jpg
IMG_20210213_155457.jpg
Last edited by amallaburn on 13 Feb 2021, 20:04, edited 1 time in total.