Relay Hdi 3.0 Engine Fault

[pikesrelaybus]

Hi,

I wonder if anyone can shed any light on this. I'm totally confused. Yesterday I went for a short drive having not used the vehicle for a week or so. At the bottom of our hill the "check engine" lamp with associated beep showed. I drove into town, did some shopping and only when coming out of a junction the engine stalled. It restarted but immediately started loosing power (like the ignition had been switched off) then back to normal. When I got home I put my read on the vehicle and got:-

 

P0235 - Turbo Charger Boost Sensor "A" Circuit and

P0638 - Throttle Actautor Control Range / Performance (Bank 1)

 

This morning, having had a good think about things, I decided to have a look and view some "live data" on my reader. Everything appears normal. I've noted and cleared the errors and did the same journey but nothing will repeat.

 

I have thoughts about the last error in that when the vehicle cut out I naturally put my foot down. I think it sensed the difference between input and go and then created this error. I have no idea why the turbo boost, actually manifold pressure error came up, that seems to work fine and changes as you drive.

 

My only thought regards the cutting out, which is quite worrying since I do a lot of long journeys is that I failed to renew the fuel filter. I have a new one but just couldn't work out how to get the top off. I subsequently read that you have to remove it completely and use a vice and strap to do the job. It's about 15k miles overdue. I have tried my utmost to make it go wrong with various driving conditions, light to heavy load, different gears etc. Now all this evidence is confusing me.

 

My only thought is that there's plenty of wires over the engine, lots of them rub up against the engine, could have caused a short, that would explain a lot, not seen anything but I'd be interested what other owners thought or had any idea's for me to check out. If an ex-service engineer in electronics can't work this out, I'm baffled if Citroen garage will sort it without charging me the earth.. Any help would be most appriciated.

[pikesrelaybus]

Just an update, having cleared the fault and had no light for a week I had a "hiccup" coming out of a junction and a few yards down the road the engine light came back on. This is the throttle position actuator fault as above. I've repeatedly cleared the fault and it just keeps coming back. I conclude therefore this is the cause of my "check engine" fault. Has anyone else has a throttle position actuator fault before. Had to change the throttle position actuator for this reason. My van has just over 60k miles and is used mostly on motorways..

[pikesrelaybus]

SOLVED!!!. Well, it was logical really, I have a throttle position/actuator fault and that's what it was. I will explain to fellow Relay/Jumper owners. This vehicle is drive by wire. Your foot position on the throttle is electronically transmitted to a motor controlling a butterfly valve on the inlet manifold, obviously via a computer to protect the engine from faults. For the untrained eye, like myself initially, the air enters from the front, is ducted through the air filter, down to the bottom part of the engine (via the air flow sensor) and ends up on the centre of the turbo, behind the engine. You'll only see this flat on your back. Then the outlet of the turbo goes via a section of metal pipe and then rubber pipe to the radiator at the front. The other side of the radiator goes up through the wheel arch and onto the end of the inlet manifold. On the manifold, which is just under a long plastic wire holder, is a sensor, mine is marked with EGR and on the end of that manifold is the throttle housing and motor bolted on to the end. I initially checked this sensor and found that it was complete fouled up but alas, the whole of the inside of the manifold is fouled up with soot, coke, oil, whatever, it's disgusting and I was surprised. I cleaned the sensor, which appears to be a temperature sensor, with gentle air from an air line, cleaned it up and refitted it. The easiest way to get the throttle body off is with a 3/4" wrench and 13mm socket on the engine side, there are four bolts holding it down. The two at the front with a 13mm spanner. Removal is towards the right having chopped off the citroen jubilee clip. You'll need a replacement 60-80mm jubilee clip. You'll be amazed at how choked up this valve will be. On mine the motor comes away from the valve assembly with two security torx bolts (the one's with a centre pin). Inspection on mine found that the motor faceplate has rusted and caused the output spindle to bind. The motor and valve interface by having opposite quadrants. Imagine a clock face cut into quarter hours. 12 to 3 = 1, 3 to 6 = 2, 6 to 9 = 3 and 9 to 12 = 4. Quandrants 1 & 3 are on the motor and Quadrants 2 and 4 on the valve assemble. There's a little rubber buffer that goes inbetween the quadrant surfaces. Apart from the binding of the motor, the valve itself was stiff with all the crap within the valve, thats just after only 60k miles. On top of this, one of the quadtrants on the valve also acts as a travel limit. The valve can only be anywhere between fully open and fully closed, nothing beyond those limits, however, yeah, you guessed it, with that bit broken it not only fouled the movement but the valve no longer had set limited and the reason for the error code. I cleaned it all up and put it back together less loose broken part to find that I could only get just over 3000 rpm, that means the motor shaft is 180 degree's out, a simply change. Now that my valve was all clean and the broken part removed it now got stuck. Once it sticks the engine drops from tickover to probably around 400-500 rpm and the throttle won't work. So, it's a new throttle body and motor, you can't buy them seperately. Citroen sell you this part for £480 however, watch out, in 2009 this "WAHLER" part was superseeded with a  "PIERBURG" model, Citroen part number 163676. It has a different connector so can't be plugged back into the vehicle directly. However, there is a interface lead, Citroen Pt Number 160645280 for an additional £191 that will allow this part to work. Both the valve and interface lead are available on eBay for £285. Check out http://www.partinfo.co.uk/files/PI%201088.pdf   for details of this change. I am awaiting delivery of mine and it will take 10 minutes to fit. I find it quite difficult to accept this high charge from Citroen when the exact same part can be obtained cheaper. I would have happily gone along to Citroen and had them fix it if I could actually afford it, I have had to look at this problem myself and despite the modern engine techniques and limited space to work, actually it wasn't reall that difficult.

[paul.h]

Thankyou for coming back to us with the solution, as you have probably guessed by the lack of help from the forum, it seems to be a problem not experienced by anyone on here. I had a look at the Citroen procedures and they call the part 'air intake case or air inlet neck' and its 4 bolts have a torque setting of 28 Nm. When I have serviced our petrol cars I usually clean the throttle body/plate since they foul up with carbon and a bit of carb cleaner soon removes it - this may work for you as a preventative measure.

[pikesrelaybus]

Indeed Paul.h, I have now confirmed, no more error codes and throttle seems more responsive.

 

As a side note, the old valve motor is a four pole "stepper" type motor, whereas the new one seems to have a standard motor in it with gears, motor brushes? who knows. Watch out bolting it back in, I knocked off a glow plug wire, soon let me know..

 

I totally agree with all the crud inside, this is a modern diesel engine. I noticed also the butterly disc is also screwed onto it's shaft, the old one was press fit possibly welded in place..