Xsara II 2.0 HDI 90 limp mode

This is the place for all your Diagnostic related questions or advice.

Moderator: RichardW

dave_xsara
Donor 2021
Posts: 331
Joined: 24 Nov 2010, 22:35
x 9

Re: Xsara II 2.0 HDI 90 limp mode

Post by dave_xsara »

Rhothgar wrote:
18 Jun 2021, 02:02
Does it hesitate around 2000rpm intermittently?
Not that I've noticed. TBH, it goes like a train now - until it drops into limp mode.
Rhothgar
Donor 2020
Posts: 1322
Joined: 22 Nov 2004, 01:21
x 43

Re: Xsara II 2.0 HDI 90 limp mode

Post by Rhothgar »

That's my point. The diagnostic code is produced when it goes into limp home mode.

So something is causing the fuel pressure regulator to reduce its cycle. Presumably the ECU limiting the fuel delivery.

Did you ever follow through with my previous suggestions or anyone elses?
Rhothgar
Donor 2020
Posts: 1322
Joined: 22 Nov 2004, 01:21
x 43

Re: Xsara II 2.0 HDI 90 limp mode

Post by Rhothgar »

Right! Just looked in my diagnostics manual and only have 0190 not and 0191 but 0190 is the Fuel Pressure Sensor and as your code mentions consistency, I would first load test the wiring between the fuel pressure sensor and ECU and Fuel Pressure Regulator and ECU.

I have re-read some of the earlier posts and it seems you swapped out the FPR but did you check the wiring not for simple continuity but the ability to accept load?

As far as FPS is concerned, I never like advising on just simply swapping things out for the sake of ease. So rule the wiring out under load please. I'll tell you the pins in a moment.

With ECU connected and ignition on, probe pins 1 and 3 of the red connector to the FPS. You should see 4.8 - 5.15V.

Probe pins 1 and 2 with ignition on.
Engine stopped. 0.5V.
FPS disconnected 5V
When engine is started and fuel pressure is 200 bar, then 1V is seen.

The fuel pressure signal should vary between 0.3V and 4.7V. Presumably 0.3 at idle and 4.7V at full throttle/full load.

I'll try and find an oscilloscope graph of mine.

If you wiring checks out OK (both on FPR and FPS), in terms of load testing, then I would change the fuel pressure sensor.

Now! Here's the rub looking at the wiring diagrams!

Pin 44 from the ECU Green 1135 is shared between the throttle position sensor, the fuel pressure sensor and the induction air pressure sensor on the intercooler.
Pin 34 from the ECU Green 141 is shared between the fuel pressure sensor and the induction air pressure sensor.

All wires to fuel pressure sensor are green! This is where it can get confusing. Wires 1414, 1415 and 1416 become 1415, 1416 and 1417 at IC60 then go off to various splices heading towards throttle position sensor (E113A - Green 1417), towards ECU by diesel pump (E141 - Green 1415) and the ECU (Pin 74 - Green 1416).

If you don't already have them, ask Marc for the 12.11 wiring diagrams for your vehicle (Well. 12.11 on the Xantia HDi).

I know of no reason why E113A splice would deteriorate other than if it got disturbed/tugged during a clutch change perhaps.

My method of diagnosis is very much self taught and I always try to rule out wiring first especially as we own Citroens before condemning a part. It's cheaper also.

You may be of the mindset of hang the expense and just get a replacement fuel pressure sensor. Someone in the group must have a known good one?

Hope this helps. I've no idea if I am 'teaching my grandmother to suck eggs' here!
dave_xsara
Donor 2021
Posts: 331
Joined: 24 Nov 2010, 22:35
x 9

Re: Xsara II 2.0 HDI 90 limp mode

Post by dave_xsara »

I don't think there is a wiring diagram available for this build version as I had asked before.
I will look into that check hopefully over the weekend.


I think someone mentioned that splice to me before - but it was in relation to delayed cut out of engine after ignition off. Will go back through the hunting thread as it might be in there.
dave_xsara
Donor 2021
Posts: 331
Joined: 24 Nov 2010, 22:35
x 9

Re: Xsara II 2.0 HDI 90 limp mode

Post by dave_xsara »

Rhothgar wrote:
18 Jun 2021, 11:20
That's my point. The diagnostic code is produced when it goes into limp home mode.

So something is causing the fuel pressure regulator to reduce its cycle. Presumably the ECU limiting the fuel delivery.

Did you ever follow through with my previous suggestions or anyone elses?
Yes, problem is that my Lexia has no way to log the data and it happens very irregularly so having the diagnostic setup in passenger seat took up too much space and I didn't want to leave the laptop lying there in view.
I did also measure the TPS values and reported them back.

I didn't get the ELM, but I think that if there is a compatible one I should probably get it. I had thought that a Lexia was required to reads the data, but I think this was mistaken.
Rhothgar
Donor 2020
Posts: 1322
Joined: 22 Nov 2004, 01:21
x 43

Re: Xsara II 2.0 HDI 90 limp mode

Post by Rhothgar »

Because TPS and FPS come off the same wires, this is why I suspect a fault in the wiring rather than an intermittent faulty pressure sensor. I think you have previously had faults relating to throttle position and fuel pressure sensor now (at different times granted but remember this is an intermittent fault - the hardest to track down). When the fault occurs, that is when the ECU logs the data.

Is the connector to the air mass meter secure? I managed to lose the blue rubber seal from mine when it disintegrated so I cable tied the connector around the MAF body. I think you were talking about that at some point too. Obviously, I have no idea what you personally do when you get this fault? For all I know, you may go around the engine bay checking connections and waggling them and resetting the fault until next time?
dave_xsara
Donor 2021
Posts: 331
Joined: 24 Nov 2010, 22:35
x 9

Re: Xsara II 2.0 HDI 90 limp mode

Post by dave_xsara »

Yes - that connector is secure. Are those values for the MAF typical? I always thought they were high, but the MAF is definitely working correctly.
I was looking up how to test wiring so I'll have to try it again. I using just put it to continuity and listen for beep whilst wiggling the connectors, but I may update the technique.
dave_xsara
Donor 2021
Posts: 331
Joined: 24 Nov 2010, 22:35
x 9

Re: Xsara II 2.0 HDI 90 limp mode

Post by dave_xsara »

Found it. I did think it was wheeler who said it:
viewtopic.php?t=59052
Rhothgar
Donor 2020
Posts: 1322
Joined: 22 Nov 2004, 01:21
x 43

Re: Xsara II 2.0 HDI 90 limp mode

Post by Rhothgar »

I made a load test lamp up with an H4 bulb but you shouldn't leave it on for long because it obviously draws a lot of current with an 100W bulb!!!

I think wheeler originally (sensibly) suggested a brake light bulb to me. At least with a bulb, you can test that a wire holds up under load. With a continuity test, you may have a beautiful copper looking wire at each end, but it there is sufficient corrosion with the wire somewhere along it that reduces the effective current carrying capacity wire of that wire down to a few strands then a continuity test with a DMM will still beep whereas a bulb would not light so brightly!
dave_xsara
Donor 2021
Posts: 331
Joined: 24 Nov 2010, 22:35
x 9

Re: Xsara II 2.0 HDI 90 limp mode

Post by dave_xsara »

Quit again this time there was a rattle at the front like something falling down through the engine bay.
Oddly, no EML came on. Will check the codes to see if anything pops up, but seems odd to quit without an EML.

Car has been parked up for a good few weeks now, lack of driving is not doing it any good. Tyres must have flattened themselves as it took about 10 miles to get rid of the vibration coming up through them.
dave_xsara
Donor 2021
Posts: 331
Joined: 24 Nov 2010, 22:35
x 9

Re: Xsara II 2.0 HDI 90 limp mode

Post by dave_xsara »

Was driving at low throttle behind a car today and the engine starting making single bangs which I knew was fuel shortage. Didn't put the eml on though for about a mile.
Waited a few minutes and then it started again.
Here is the fault p1112.
Attachments
IMG_20210911_193708.jpg
wheeler
Posts: 5112
Joined: 21 Sep 2002, 19:07
x 290

Re: Xsara II 2.0 HDI 90 limp mode

Post by wheeler »

OK as per your PM. Cutting out that yellow connector certainly wont do any harm & they can be troublesome but normally the problem this causes is the engine runs on for about 5 seconds after turning the key off. It also usually logs a fault code something along the lines of 'fuel pressure regulator stop requested but still active' (or words to that effect). Like i say it wont do any harm to chop it out. If i remember right the wire colours are different at each side of the plug so best to cut & re join them one at a time.
I also notice that the fuel pressure when the fault occurred is only 31 bar, if there is a fault with the fuel pressure sensor or its wiring i would normally expect to se a default value reading which from memory is around 450 bar. The fact it is showing such a low reading kind of suggests that the fuel pressure is actually low. Now i've only skimmed over all the previous posts so i may have missed this but has the low pressure fuel pump been replaced? last thing i remember reading is that it was replaced around 15 years ago? I would say getting anything more than 5 years out of one of these pumps is a bonus. It may be cutting in & out. If you disconnect the fuel pump when the engine is running it will run for about 5 second then splutter out, it could be stopping then kick back in after going over a bump.
Unfortunately being so intermittent it could be a pain to pinpoint this fault. If this was mines & the LP fuel pump was over 5 years old i think i would be replacing it.
dave_xsara
Donor 2021
Posts: 331
Joined: 24 Nov 2010, 22:35
x 9

Re: Xsara II 2.0 HDI 90 limp mode

Post by dave_xsara »

Hi wheeler,
thanks for the reply. Yes we had thought initially that it was the in-tank pump, although I did do a check and the voltages where as expected. I'll swap it out and see what happens.

Thanks for the feedback.
dave_xsara
Donor 2021
Posts: 331
Joined: 24 Nov 2010, 22:35
x 9

Re: Xsara II 2.0 HDI 90 limp mode

Post by dave_xsara »

Can one of the mods confirm the OEM number for my fuel pump please?
wheeler
Posts: 5112
Joined: 21 Sep 2002, 19:07
x 290

Re: Xsara II 2.0 HDI 90 limp mode

Post by wheeler »

Should be 1525T4