Tempreture sensor for ECU **update**

Stuart McB · Post by **Stuart McB** » 22 Jul 2004, 02:13

Still have that small problem with my revs staying high now and again [:(]. Been to Citroen to day who told me it was the map sensor. DOUBT IT!!! the car ain't cutting out it's just reving a little to high (1200 instead of 850to 900) and there's no fault code being kept. Now this afternoon after the engine has cooled down I've cleand and put back the idle speed valve thing and gain and all is well. But I'm thinking as the car starts OK, runs fine when cold only when up to temp this problem occures. Could the problem be a duff temp sensor (green plug) to the ECU? Phoned Local GSF, dealer only part [:(] Do think that some where like Hal**rds would sell such a thing or a large motro factors? Got a big place in Birmingham called fletchers does all this kind of thing for older cars. Sorry its a Xsara 1.6 VTR 98 model. I'm out and about tomorrow so could pick one up when in town.

AndersDK · Post by **AndersDK** » 22 Jul 2004, 05:08

The ECU engine coolant temp sensor (CTS) is responsible for the correct "choke" action.
However if the CTS were at fault, then it would most likely be disrupted (hi ohmic), which in turn is read by the ECU as a cold engine. The result would be a richer mix with hot engine, which most likely the Lambda sensor would tell back the ECU, and then the fault lamp should come on ...
But that's in a perfect world ...
You could test the green CTS with an ohm meter. Should read LO ohms (some 1-400 ohms) when hot, and some 10X that when cold.
It's not the precise ohmic value that counts, but the large shift in ohmic value over temp.

XM-V6 · Post by **XM-V6** » 22 Jul 2004, 13:22

from book PH Olving:
resistance at 10°Celsius 3780 ohms, at 20°C 2500 ohms, at 30°C 1690 ohms, at 40°C 1170 ohms, at 50°C 820 ohms, at 60°C 590 ohms, at 70°C 430 ohms, at 80°C 320 ohms, at 90°C 240 ohms, at 100° C 185 ohms

dave.t · Post by **dave.t** » 22 Jul 2004, 14:27

had the same kind of problem on my xantia 2.1td which turned out to be ecu coolant sensor this wasn't recording the fault either .it cost £10 from the main dealers so its well worth the gamble.
dave t.

Stuart McB · Post by **Stuart McB** » 22 Jul 2004, 16:18

Just been to local Citroen Specialist in Birmingham. They did a free diag test for me and came back withthe following codes readings.
MAP sensor unplugged
MAP sensor unplugged
Idle speed sensor Unplugged.
All of which were from me taking off and re-connecting.
Now the mechanics had a good look about and double tested the temp sensor for ECU as I asked about it and it was well within it's specs. However they did noticed that the tappets needed to be ajusted as they were a little rattly, I was getting round to do this later on next month. Any how because the valves are a little slack they recon that if it aint the idle valve then it's the plugs and leads. So for £40 they'll ajust the tappets, check plugs 'n' leads and put back together. If any thing the tappets are being done.

Stuart McB · Post by **Stuart McB** » 27 Jul 2004, 00:18

Just had the car back from the garage and it's purring like a kitten. The tappets have been ajusted and the car now seems more responsive then before. Tick over is a lot smoother and the revs seem alot, lot less. No ticking over at 850 to 900 and no sign of the intermitant fault.

Stuart McB · Post by **Stuart McB** » 28 Jul 2004, 20:45

BAH and double BAH!![:(!][:(!] the fault is back again. So it's been back to the garage who did the tappets for a diag test. Nothing, but joy of joy it did it's thing while there with the mechanic looking at it [:D]. He had a good long think checked all the usual suspects like MAP sensor, Temp sender to ECU etc and came back with 'idel speed valve'. Now Citroen say "back order and £138 + VAT,". No chance mate. Have found a source on the webb who after faxing a picture given to me by Citroen at the dealers quoted me £51 +vat and £4.50 delivery from the manufacture or equivilent. SOLD, should be here for Friday morning.
Seems to be on the ball. have a look. www.autoteknik.co.uk

Paulxmski · Post by **Paulxmski** » 30 Jul 2004, 00:50

Hi Stuart,
Seems similar to the problem I've been trying to track down on my V6. The site you have pointed at seems good and I might go there if it proves to be the same item - thanks.

Stuart McB · Post by **Stuart McB** » 30 Jul 2004, 20:09

Paulxmski. The part arrived this after noon. Problem. Right part wrong engine management set up. I ordered like a pra** a magnetic marrelli part, DER!!! should have been Bosch. Any how re-orded and should get tomorrow if all going well. The right part is only £15 inc posatge more so that's still nearly £90 cheaper then Citroen.

Paulxmski · Post by **Paulxmski** » 31 Jul 2004, 02:42

Hi Stuart,
I'm looking forward to knowing if it solves your revs problem as I bet you are.
Paul

Stuart McB · Post by **Stuart McB** » 07 Aug 2004, 01:20

well have fitted the idle vacume valve (right part) and fitted some new Bosch '4' super plugs so far so good. Apart from on the day a little ruff some injector (STP)cleaner has been put in the tank all seems well. No over reving and I have been giving it a kicking. Just on the safe side I'm going to replace the ECU temp sender any way as I have it to hand and it only cost £14 from Citroen.

Stuart McB · Post by **Stuart McB** » 10 Aug 2004, 00:19

OK then it's been a couple of days now and 150K. Changed the Temp sensor to the ECU on the weekend and took for a spin. The revs from cold were alot less only 1150 instead of the 1500 I'd been getting. Any how the cold start came off a lot earlier aswell. The car's been running fine with no glitches [:D]. So it must be a combination of idel valve, ECU temp sensor and some cack petrol as after a fill up at Sainsburys all has been well.[:D] Thanks for all the replies. As for the sensor, ordered the ECU one using the vin number at the Citroen dealer and it was green with a yellow collar just like the manual said but the one I removed was Blue with no collar. The temp sensor for the guage was also blue with a violet collar just as per the manual. Looks like a replacment was fitted but the wrong part used.

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Tempreture sensor for ECU update

Tempreture sensor for ECU update