Synergie 1.9TD excess noise ..update.

ebod · Post by **ebod** » 10 Feb 2005, 23:41

Hi all,
Further to these previous posts:-
http://www.andyspares.com/discussionfor ... C_ID=10775
http://www.andyspares.com/discussionfor ... C_ID=11055
I've spent a morning on the car earlier this week and gone over all the wires/earths with a fine toothcomb.But everything looks a-okay to me. So I basically decided to throw myself at the mercy of Lythgoe Citroen in Rochdale. Although I told them I'd had the fault codes done independantly, they said they would have to do their own code check and they wanted £52 for this. I was okay with this so long as they could conclude what the problem was.
All they could do was give me the same bunch of codes that the Stockport Cit Repair specialist gave me, and they said it would cost hundreds&hundreds in man hours to track down what was wrong. When I politely reminded them I already knew the codes, a guilt streak must have crept in because they only charged me half price for the diagnostic.[8)]
Here are the codes:-
http://freespace.virgin.net/ian.jarvo/faults.jpg
To summarise the problem from the previous posts, my 1998-XUD9-TFY(cat)engine is pinking and the rev counter is intermittantly working.
The advance timing solenoid is working in some form because the engine goes mega-noisey when its inplugged ( also theres a definate 5v feed).
Today I've also checked the voltage to the lift sensor and theres 13.5v available. Plus I've done a continuity check to the ECU from the lift sensor plug and thats all okay[^]
Therefore to go back to the permanent fault codes , can anyone please guide me further to help isolate whether my ECU is spooked or could something else be making the lift sensor,throttle sensor & temp sensor all fail to function. Heres the wiring diagram again for reference :-
http://www.autoelectric.ru/auto/peugeot/806/dhx/dhx.htm
Cheers

cit-tech · Post by **cit-tech** » 11 Feb 2005, 01:32

if you have a bosch ve pump check throttle potentometer
cut plug out of needle lift sensor

AndersDK · Post by **AndersDK** » 12 Feb 2005, 18:51

D1388 is the cable screen, which must be connected to earth at some point.
D132 is obviously an earth connection then.

NiSk · Post by **NiSk** » 12 Feb 2005, 21:44

Don't jump to hasty conclusions! The diagram definitely shows the sheilds of several cables connected together - but that doesn't necessarily mean that they are all earthed to ground potential. I'd take it very carefully there - you don't know what logic levels are being used.
//NiSk

Post by **philhoward** » 13 Feb 2005, 00:07

D132 is earthed at one end of the cable (standard signal cable practice), but inside the ECU (via pin 23), not on the body. There may be some kind of isolation to vehicle earth, but there's a 99% chance that it will link to the earth body eventually.
A screen is an "anti-aerial"; normally either a thin foil or braided wire around cables to protect from stray interference. The smaller the signals, the more important it is. Try a good SCART cable (with good screening), and a cheap one (with little or no screening); wave it around the mains cables...then you'll know what screening is!

DarkendViper · Post by **DarkendViper** » 13 Feb 2005, 00:16

I had an intermediate rev counter and it was cured by changing the TDC sensor. This has made the revcounter work all the time. When I removed the old one, the end had exploded off it and was showing the bare copper wires.
Might be worth changing to rule it out if not already.
Ste

Post by **philhoward** » 13 Feb 2005, 14:21

Most likely...or it could be just inside the ECU connector........whichever was cheapest to produce!

Dave Burns · Post by **Dave Burns** » 13 Feb 2005, 17:01

I don't know that there should be s much as 13.5 volts to the lift sensor, sounds wrong to me that, will measure what it is on xant when it comes back if I get chance.
Dave

ebod · Post by **ebod** » 13 Feb 2005, 23:24

Okay, this afters I got the voltmeter out on the car. I deliberately took it for a run. When cold, it sounds like a bag-of-spanners but when its warmed up its just a bag-of-nails.
Whilst running(warm) I unplugged the following :-
- Lift sensor : no effect
- Potentiometer : no effect
- Advance timing solenoid : went like a bag-of-spanners
- EGR soleniod : no effect
- Fast Idle electrovalve : no effect
- Coolent temp sensor : went like a bag-of-spanners
- I didn't do the TDC this time, but previously the result was bag-of-spanners and dead rev-counter. Remember the code read did not flag up a faulty TDC sensor.
With each of the above unplugged I took a voltage reading and the following table has the figures in the remarks column :-

If I could be 90% sure the lift sensor was dead I'd be happy to replace injector n03, but since my code reading suggested 4 permanent faults I'm not so sure whether the ECU is sick or not.
EG the code report suggesed the temp sensor was shorting to earth, however it did have an effect when I unplugged/plugged it....
The Synergie Saga continues.....[;)]

Wookey · Post by **Wookey** » 14 Feb 2005, 00:47

I'm glad I've decided to stay away from this ECU lark for one more generation of car (It's probably going to get impossible next time round, short of having a very old vehicle).
If only they put free software in these things then at least you could see what the hell was going on, but they really don't seem to make it easy. I sympathise with your difficulties ebod - it does seem to be hard to work out exactly what is going on.

Wookey · Post by **Wookey** » 15 Feb 2005, 06:48

Hmmm - interesting idea. I don't know what the signal fom the sensor looks like, but it does seem that it ought to be detectable with a logic probe set to CMOS so it is 12V tolerant. I don't know how reliable a logic probe would be in the electrically noisy environment of a car, but in principle it should work. A scope would be more reliable but presumably you haven't got one of those? This signal is very slow by electronic standards (<100Hz). A decent multimeter often has a frequency counter option which would also probably detect this signal.
The problem will be that you won't be sure it is showing nothing unless you can show that it does detect something on a good one...
Hmm - I wonder if you can just connect a speaker up to the signal - it's going to be in the 9 - 100Hz range (asuming it give one blip every other engine revolution) which is (above 20Hz=2400rpm) audio. A small speaker ought to make a noise varying with engine speed, unfortunately the rate is a bit low so you probably won't be able to hear it over the engine noise, as it won't work at idle. Just an idea.

Richard Gallagher · Post by **Richard Gallagher** » 15 Feb 2005, 12:51

Would not not be cheaper/easier/lot less head scratching to just change the pump for an earlier non ECU model?

Richard Gallagher · Post by **Richard Gallagher** » 15 Feb 2005, 13:24

"Its not going to beat me".
I know that feeling only too well, its cost me quite a lot over the years!!
Good luck.

NiSk · Post by **NiSk** » 15 Feb 2005, 13:48

Sorry to name the obvious - but can't you just adjust the pump timing manually once its warmed up so that the "bag of nails" sound returns to the normal running noise level of the engine? Then when its cold it should only sound like a bag of nails instead of a bag of spanners.
I know that the engine of my '93 XM TD12 (non-electronic) sounded like a bag of spanners when i got the pump timing one tooth out while replacing the cam belt.
//NiSk

ebod · Post by **ebod** » 15 Feb 2005, 23:43

I don't know how to manually adjust this derivative of the VE4 pump.
But if I end up concluding the ECU is buggered then it would be probably cheaper to put the bits of the 'original' timing control mechanism on it from a ~95-97 xantia or 405/6.
In my surfing I've found a 2nd hand ecu for £150 & and a n03 injector for £40.
This place might come in handy for fellow poster Wookie :-
http://www.midlandmpvbreakers.com/