ECU Gearbox Fault code U1209 (DS3 Citroen) Auto & Limp mode

[odysseik]

Ok. which one should I buy? there are so many brands etc, im so confused, I want to buy good one (not cheap).

[Hell Razor5543]

I would first consider looking on the GSF website. While they don't manage to keep everything up-to-date, they may have the part you need. You will need to enter your REG into the box so as to get the right parts. When I had to get a replacement switch for my previous C5 I got one made by Febi, as that is a known maker.

I would advise against looking at Euro Car Parts. While some forum members have had good service from them, others would not touch them with a barge pole! They have the nickname "Euro Crap Parts".

[odysseik]

I just bought from GSF and switch brand FACET. Tbh GSF is expensive compared to the other sellers, but the delivery was free in my case and I'm expecting it within 3-4 days. Also UK based. I would've bought from the other European ones with long deliveries but I really have to fix this asap.

[odysseik]

Just a note, as I'm waiting for the switch to arrive.
Lately quite OFTEN when start driving it shows Dash(-) instead of D(drive), especially right after quick or harsh acceleration on 1st gear.. and when on Dash, I'm not sure but I don't think that it changes gears at all..(which could be limp mode I guess).

According to the manual handbook the Dash(-) means: "gear is not engaged correctly(selector between two gears)"......

I'm so confused and the more I search the more I tend to believe that a brake light switch won't fix the issue.

[Hell Razor5543]

That has happened to other Forum members, and a common cause is the switch on the gearbox (that 'tells' the ECU the position of the 'gear' lever. As I don't have an automatic (so have not experienced this problem) I cannot offer any further information.

[odysseik]

Update: The switch will be fitted next week. In the meantime I noticed what's the issue. The issue is between the Neutral and Drive on the gearbox lever. The gearbox is either too loose or something, because most of the times I put it in N it doesn't get it and on the Dashboard I only see a dash(-). And when I put it on Drive it only sometimes it shows dash(-) too, but that's because the lever it feels very 'slippery' or 'loose'. I know that for sure as even without braking I can still can push the lever slightly towards N and it'll go into dash(-) and probably limp mode. And trust me I use very little pressure to do that.

It should not happen. For example when is on P or R, it never feels loose and it never 'slips'. Only when is on D or N it feels slightly loose, it's like you can kind of put it in between, and like it feels loose even when not braking, which is ridiculous. If it was stiff and strong enough when on D, this will never happen.

So now I start doubting that a brake light switch will fix it.... even though I called 4 different specialist and ALL said that if the fault says brake light switch, then I should first fix that and see.

What do you guys think?

[Dragon4331]

Hi mate any luck with the problem you was having as i have a ds3 1.6 automatic i run a diagnostic on it got fault code U1209 communication gearbox intermittent no lights on dashboard or anything just when i drive it goes in the 1st gear the holds back in 2nd then goes in 3rd any advice for me please

[DeeSingh]

I bought a 2014 DS3 1.6 Auto VTi recently for my kids and regretting it.
First Issue - after doing about 80 miles on the motorway the car started to Jerk slightly when going from 1st to 2nd gear in traffic. Managed to get home fine. Next day drove around locally for over one and half hours and it drove fine, the only issue being a slight vibration in 1st gear and when coming to a stop in the last meter until you fully pressed the brake. Was advised to have the gear box oil changed which I did. The car seemed to be driving smoother and better for a couple of weeks but then whilst drive up a very steep hill it threw a engine management fault, It didn't effect the drive of the car in any way, didn't go into limp mode or anything like that. Took the car to a Specialist: he printed out the following codes:

From Engine Management ECU/Fault reading
U1213 – CAN network
Status - Intermittent Fault
Nature of Fault - Fault in communication with ABS/ESP ECU

U1209 – CAN network
Status – Intermittent Fault
Nature of Fault – Communication fault with the gearbox ECU

P2196 – Upstream oxygen sensor signal
Status - Permanent fault
Nature Of Fault – Mixture too rich

P0172 – Mixture Regulation
Status – Intermittent Fault
Nature of Fault – Mixture too rich

From Anti-Lock Braking System (ABS) or (ESP) Fault reading:
U1209 – Fault no communication with automatic gearbox ECU
Status – Intermittent
Characteristic of the fault – Data Invalid

Codes have been cleared, They've not reappeared in over 2 weeks but guess we've been avoiding steep hills. The cars never gone into Limp mode.
Specialist's recommendation is "We Buy Any Car".
Going to try new air filter and Plugs first, then get someone to look at fuel injectors. then maybe Timing Chain as the garage who changed the gearbox oil said the Oil was very bad and Engine/Gearbox a little noisy.

[GiveMeABreak]

It would help if you provided the VIN so I know exactly what gearbox you have. Please post your VIN in full without spaces - it will be automatically masked from public view after submitting your post & will only be visible to staff.

[DeeSingh]

Hi Marc,

VIN number is VF7**************[VIN obfuscated, can be read by forum staff]
Thankyoi

[GiveMeABreak]

Ok, so this is the EP6C 120 Engine with AL4 Automatic Gearbox.

These are the fault code descriptors for you:

Fault Code:	U1209
Description of Fault:	Communication with the automatic gearbox ECU missing. Information from the gearbox Data invalid.
Conditions for Fault to clear:	After switching the ignition off and then back on
Downgrade Modes whilst Fault is active:	Cutting of all ESP operations
Symptoms:	-
Suspect Areas:	Automatic gearbox ECU

Fault Code:	U1213
Description of Fault:	ESP function fault: Coherence. ESP system fault. Fault confirmation time: Immediate. Conditions of activation of the diagnostics The following conditions have to be met: - engine running - Vehicle in motion - Check that there are no fault codes - U1003 (CAN communication fault (Missing/interference) : No signal) - U1113 (Fault in communication between the automatic gearbox (BVA) and the ABS/ASR (ESP) : No signal)
Conditions for Fault to clear:	-
Downgrade Modes whilst Fault is active:	No taking into account of the requests from the ESP
Symptoms:	-
Suspect Areas:	ABS/ESP ECU Main harness Automatic transmission control unit Engine ECU

The following code has different meanings depending on the version of Bosch Engine ECU, so I have listed both. You can see which you have by looking at the label on the ECU.

Fault Code:	Engine ECU BOSCH MEV17.4EVO P0172
Description of Fault:	Mixture regulation fault: Mixture too rich. Richness regulation at the poor end (correction relative to the richness measured between the upstream and downstream oxygen sensors): system too rich. Conditions of activation of the diagnostics The following conditions have to be met: - Engine management ECU in main triggering phase - Engine temperature greater than -7,5°C - The diagnosis is performed as soon as the regulation of richness upstream of the catalytic converter is triggered
Conditions for Fault to clear:	Mixture regulation correct
Downgrade Modes whilst Fault is active:	-
Symptoms:	Unstable idling Stalling at idle Lack of power Flat spot on acceleration Emissions outside the norms
Suspect Areas:	Fuel injectors Canister purge electrovalve Sealing of the air inlet manifold Downstream oxygen sensor Electrical harness

Fault Code:	Engine ECU BOSCH MEV17.4.2 branch 2 P0172
Description of Fault:	Mixture regulation: Mixture too rich. Richness regulation at the poor end (correction relative to the richness measured between the upstream and downstream oxygen sensors): system too rich. Conditions of activation of the diagnostics The following conditions have to be met: - Engine management ECU in main triggering phase - Engine temperature greater than -7,5°C - The diagnosis is performed as soon as the regulation of richness upstream of the catalytic converter is triggered
Conditions for Fault to clear:	Mixture regulation correct
Downgrade Modes whilst Fault is active:	-
Symptoms:	Unstable idling Emissions outside the norms Excessive fuel consumption
Suspect Areas:	Fuse Setting the timing Electrical harness Air inlet circuit Fuel circuit Engine fusebox Upstream oxygen sensor Exhaust manifold Catalytic converter Engine compressions Variable valve lift system

Ditto for the following code:

Fault Code:	BOSCH MEV17.4EVO P2196
Description of Fault:	Downstream mixture regulation fault: Coherence. Error in plausibility between the 2 oxygen sensors. The upstream proportional oxygen sensor indicates "rich mixture" while the downstream oxygen sensor indicates "poor mixture". Conditions of activation of the diagnostics: The following conditions have to be met: -Engine management ECU in main triggering phase -Regulation of the downstream oxygen sensor active
Conditions for Fault to clear:	Downstream sensor voltage plausible (For at least 2s)
Downgrade Modes whilst Fault is active:	-
Symptoms:	Emissions outside the norms
Suspect Areas:	Proportional oxygen sensor

Fault Code:	BOSCH MEV17.4.2 branch 2 P2196
Description of Fault:	Upstream oxygen sensor signal: Mixture too rich. Error in plausibility between the 2 oxygen sensors. The upstream proportional oxygen sensor indicates "rich mixture" while the downstream oxygen sensor indicates "poor mixture". Conditions of activation of the diagnostics: The following conditions have to be met: - Engine management ECU in main triggering phase - Regulation of the downstream oxygen sensor active
Conditions for Fault to clear:	Downstream oxygen sensor voltage between -0,03 V and 0,03 V for 2s.
Downgrade Modes whilst Fault is active:	-
Symptoms:	Emissions outside the norms
Suspect Areas:	Electrical harness Upstream oxygen sensor Engine ECU Fuse Engine fusebox

[DeeSingh]

That just looks complicated and expensive, but thankyou for the detailed information. Will try a find a mechanic who's happy to take a look for a couple of hours at least.

[DeeSingh]

Good Morning,
Could you help with another problem please.
I've got to the stage where no one could fix the issues so the car has been sold as spares and repairs, Its being collected tomorrow but now I have another problem, It won't start, no power, looks like a short somewhere because the dash lights come on when I turn the ignition key but the then dies before the engine even tries to turn. Is there anyway to get the car out of PARK mode with no power?
Regards

[GiveMeABreak]

It's probably the Shift-Lock preventing this and with no power it will need manually unlocking.

Unlock the "shift lock" by pressing at "a" with a screwdriver. You'll first need to remove the surrounding centre console trim.
Move the selector lever to disengage it from the "P" position.

[GiveMeABreak]

Please don't create separate posts for the same issue. It causes duplication of answers - you other topic has been deleted.