2.8crd fault code P0487
 

It seems this fault code relates to EGR Airflow - Throttle Control Circuit A Open. I wonder what Circuit A is? I also wonder about the Throttle Position Sensor, which must surely be a part of the circuit and must be a moving part that could fail?

The car (instrument panel) tells me the above fault code, but if I take it to a garage they say it is something quite different - P 0402 which is Excess EGR flow - I suppose there is a relationship.

Does anyone have any experience with this problem or know a 2007 Grand Voyager with a 2.8 crd VM Motori diesel engine well enough to tell me where to look for the TPS?

Many thanks

I've checked what info I have and I cant find any mention the 402. The only reference to the 402 code is on the later shape 2008 models.

link to the procedure for the P0487 here
https://docs.google.com/open?id=0B_2...XNuajBkeWlWVUE
https://docs.google.com/open?id=0B_2...G5GdGpvdHVlRmc

I'd suggest a 24hr subscription to techauthority.com if you want to check out the 402

Regards

Richard

Thanks Richard:
It is quite interesting because the 2.8crd has an EGR Valve assembly that includes what VM call a Throttle Valve just prior to the Intake Manifold. When the light first came on I took the car to a Mercedes garage in the Czech Republic who service Chrysler, they said that there was a vacuum system leak caused by a cracked manifold on the solenoid that controls the "Throttle Valve" and they glued it as a temporary repair. The light was out for about 30 miles and then came back on again.

Is the "Air Flow Control Valve" the same as "Throttle Valve"? I assume so and if so I have already replaced the glued solenoid - which controls that valve - although I have not checked electrical continuity. If you suck on the vacuum tube you can see the valve move.

It seems to me that the fault code refers to an electrical problem of some kind and I am becoming very concerned about the ECM - especially as it has modified software for better mileage.

I should add that the engine performance seems normal, except that it is burning more fuel and I sometimes think it changes down more readily.


I looked at Techauthority, but it does not seem to list the (European) 2.8crd Grand Voyager

Regards

hmmm....

I cant find any mention of a Throttle valve in the documentation I have, I've checked the pin-out for the ECU plugs and there is nothing there suggesting a control function for a Throttle valve.

Have you got a photo of the part?

If techauthority cant find your VIN, just select the year, and RG body and engine size and you'll get the info. Use Internet Explorer as well as it comes up funny in Firefox or Chrome

Regards

Richard

- your post doesn't have a country flag letting people know your language
- what we in the UK call a TP [s] our American cousins call an APP [s]
- note the chrysler workshop manual [s] call it an accelerator pedal position sensor

TP [s] - throttle position sensor
APP [s] - accelerator pedal position sensor

NOTE, any info available is written by the Americans / Canadians in American English, if we don't use their 'term' for something we will never find it. One example might be 'tyre' & 'tire' so people with the best will in the world will never find a reference to a TPP or TPS, because it doesn't exist, its written as an APP or APS.

The only symptom you have is that it seems to be burning more fuel, what is your average consumption ?, my old [ish] 05 with a 41TE box returns a consistent up~an~down average of 33mpg, what's yours ? and are you sure its not cheepo supermarket or crappo Russian fuel ? Best of luck

OK I will have to sort out the flag bit, but I am in the UK and my car is a 2007 Grand Voyager with VM Motori 2.8 common Rail Diesel.

This adventure started with an engine warning light coming on as I was approaching Folkestone on my way to the Czech Republic. When I got to the Channel Tunnel I checked oil, etc, etc, and as the engine appeared to be running OK I decided to continue.

When I got to the Czech Republic I found Chrysler service was mainly done by Mercedes folk so, not wanting to keep going "blind" I took the car to a Mercedes/Chrysler Service shop and asked them to troubleshoot. My wife speaks Czech and I dont, so the result was not entirely clear, however they said thay found a crack in a valve that was causing loss of vacuum and thus the warning light. They put glue on the crack as a temporary repair and sent me on my way. It was good service, but it only lasted for about 30 - 40 miles before the light came on again. So I drove home with the light on! The only obvious difference being greater fuel consumption by about 15% and perhaps more frequent down-shifting.

When I got home I decided to find the glued part. It turns out is is what VM Motori call the Intake Throttle Valve Actuator which is a pneumatic servo that sits about in the middle of the intake valve/manifold. I bought a replacement from VM and replaced it, just in case, but it made no difference.

I took the car to a local garage and they said the OBD code was P0402. They removed the combination EGR/Intake Throttle Valve and cleaned it. Meanwhile I had discovered that by playing with the ignition the car itself would tell you the code that concerned it, so I tried that and the car insists it is P0487, not P0402. I have tried Googling that but have had little success as it seems to be a propriatary code meaning slightly different things to different manufacturers, however, "EGR Airflow Throttle Control Circuit A Open" or "EGR Throttle Position Control Circuit" seems to be the thing to consider.

I dont think the 2007 Grand Voyager has a throttle position sensor, as such because it seems to be "fly-by-wire" and no doubt uses information from that system to control the "Intake Throttle Valve" and that along with temperature and other sensors likely controls EGR, however, the car runs and cruise control is also fine, so the "Intake Throttle Valve" must be opening which, surely, it would not if the P0487 fault was real?

The data I recived with the first reply had to do with shorts and other electrical defects in the Intake Throttle Valve circuit, but again, it is working and I have replaced the solenoid already.

If the OBD is reset, the lite will stay off for 10 - 30 miles and then, with a little chime, reappear.

So what is going on?

As for mileage I had my ECU (ECM) reflashed when I got the car and was, for several years getting 40MPG or thereabouts on long trips. I found that the little box of tricks route did not work for the 2.8crd - although it does a good job on my wife's Skoda.

I hope this explanation helps with your understanding of why I brought my problem to this forum?

And yes, I was born in the UK but have lived about half of my life in Canada where I worked as an aircraft engineer, so the tire/tyre controversy is known to me...

Ciao (as they say at VM Motori)

Mike (vrm8883)

Richard: Yes and no! I do have a drawing that is a pdf and would be happy to post it, if I could figure out how!!

I cant find any mention of a Throttle valve in the documentation I have, I've checked the pin-out for the ECU plugs and there is nothing there suggesting a control function for a Throttle valve.

[/QUOTE]

Well, Richard, the 2007 seems to have a fly-by-wire throttle/accelerator/gas pedal with the result that the "throttle valve" is vacuum controled by the ECU via a servo that is similar to the EGR servo, but is a different shape, with a different shape plug - to make sure there is no confusion between what plugs in where I suppose...

if you send me an email - mike@aeroventures.co.uk I will send you the drawing of the intake system which, with the EGR, which is in the same casting, is at the front of the engine now - I think the EGR used to be at the back and some of the pictures I have show throttle cables. I can take a couple of photos too if you like and send the lot by email as I cant find a way to do it here.

vrc8883

Yours is the RS, here is a Chrysler RG Diesel supplement for a 2005. Its a start, covers all CRD's including the 2.8.

Thank you QinteQ although the RS seems to be Petrol models only and the 2005 although the RG mentions the 2.8crd that is about it - all of the diagrams refer to the 2.5 which seems to have the ERG valve at the back of the engine and does not seems to have an Intake Throttle Valve, with associated circuitry at all. The code P0487 seems to identify this Throttle Valve which has the purpose of causing vacuum in the intake manifold that helps draw exhaust gas from the ERG circuit (when that valve opens. For reference, both valves in the 2007 Grand Voyager are in one casting just prior to the intake manifold with actuators/servos on or around the intake cam cover also at the front of the engine, near the oil dipstick.

I would like to find manuals for the 2007 model, I cant find any 2007 2.8crd on Techauthority.com and they say my VIN does not exist. The 2005 RG you kindly shared does not provide the help I need, especially when it comes to the Intake Throttle Valve. And I suspect ECU wiring may be different too. I actually wonder, as your car has a 2.8, if it has the EGR valve at the back or at the front as it might be a change that came along in later years as an "improvement"?

Ciao

Best of luck on finding a suitable manual, I've been looking for a year. Even money can't buy one. The American lads are brilliant at helping folks from other countries, unfortunately CRD's are like hens teeth in America so they can't help.

Read again the 3.2.2 ECM OPERATING MODES

The ECM uses lots of sensors in all 7 modes to adjust fuel quantity and
fuel injector timing. So on / startup / normal / overheat / limp / overspeed / after-run are all adjusted by the ECM.

NOTE : Taken from the 2005-RG-Diesel-Powertrain, best of luck !

Thank you QinteQ and thanks to TFB (Richard) too.

There is a lesson to be learned here I think. I just got back from a mechanic I trust in Solihull. we tested the Air Throttle Valve (OK) EGR Valve (OK) and visually saw them working. In fact the only thing we found that seemed wrong was Air Mass Meter voltage wich was 2.89 insters of 3.5 or so. Clearly, the Air Mass Meter was operating within its fault parameters, but it was giving bad information to sensors monitoring EGR and Throttle Valve. We took the Air Mass Sensor apart and cleaned it with an impressive BG product - it was very dirty! Since then I have driven the 50 or so miles home again without a MIL. So the lesson is do not take a MIL at face value. The Air Mass Sensor was withing MIL limits, but not good enough not to upset other sustems that were trying to match their performance to the information they were getting, which was in error.

At least I hope so!

It is worth saying that any engine parts you may need now or in the future should be bought at JNL Engineering in Camberley (01276 63278) ask for Shane. Cost of VM parts from them (they are the UK VM distributor) is about 60% less than your local Chrysler dealer. Equally, if you are looking for an intelligent mechanic, consider Matthew Wisemman at Wiseman Motors, Solihull. "It has been said an engineer is a man who can do for five shillings what any fool can do for a pound...."

Mike

Glad you got it sorted, and you are right that fault codes need to be interpreted and the live data to be viewed to get to the root cause of the problem.

Regards

Richard

Mine 2.8 CRD ('05) was running with MAF plug disconnected without any problem :confused: and with the MIL light off...
How is it possible?

MIL bulb removed?

Most ECU's will use a default value for airflow based upon load, engine speed, manifold pressure etc should there be no reading from the MAF, but performance and fuel consumption won't be optimal.

Regards

Richard

Are you serious joker2CV or just living up to your name? I really dont know anything about the layout of the 2.8 in 2005, but I would not be surprised to find that it is different from the 2007. I already wonder if the 2005 has a throttle air valve becuase there seems to be no mention of it in the data posted by QinteQ. Even so, how would you, or the ECU measure the amount of fuel to be added without a MAF? Yes, you would have throttle position and engine speed, but engine speed is surely a result rather than a measured parameter? To be honest I would have thought MAF to be rather critical. But, a few months ago I had a broken pipe from the exhaust manifold to the EGR cooler, so the EGR han nothing but air to work with - and no light.

As I think I tried to say before thse lights should not be considered Gospel truth. If I had had a code indicating the MAF it would have been a no-brainer, apparently, brains are still required!IN fact the light was caused because systems downstream from the MAF could not do what the MAF was suggesting they should and so they assumed they had a fault - they did not assume a fault with the information from the MAF because the MAF was reporting it was operating within limits (just). So the throttle valve assumed a defective control circuit and the EGR returned too much flow - wich there would have been if the MAF information was correct, and I could not figure out what was possibly wrong with those two functions and was ready to say the ECU was at fault until it was discovered that the MAF was outputting a low voltage.

There again, we had my engine running with the air pipe from the turbo disconnected so we could observe the airflow valve and EGR operation and it was running - without MAF or Turbo - I could not say how well though and I am sure it is running better with the inlet air re-connected, it even sounds better. So Richard is probebly right.

Mike

I'm serious, 2005 is different from 2007: no throttle valve and different EGR.
@TFB: the bulb is ok, not removed ;)

vrc8883,

- all of them
- the RG's
- the non CRD RS's
- the Diesel Powertrain 01
- the Diesel Powertrain 02

Hope this helps, that's why we are each of us supposed to be here for.

Thank you QinteQ: I appreciate your support

Mike

Hi. Is there anyway to access the links above? Now it says page not found. Thanks so much!