P02E8 Diesel intake air flow “a” position sensor circuit low

[drover]

If you have been toottling around, idling a fair bit, it may be just oil coating a sensor , so a good burn down the road if you can for 20 mins or so often gets rid of these sort of things...
Last week at a mates place I had spent a few days just tootling around his town and the Jeeperific wasn't happy at all, stop at lights and rough idle, so when we went back to our camp we went for a blast down the road and back, all good, might have been trying to do a burn, so a fast run seemed to do the trick and later looking at the data it seemed like the same time it did a burn .................

[vijith555]

Originally Posted by drover

If you have been toottling around, idling a fair bit, it may be just oil coating a sensor , so a good burn down the road if you can for 20 mins or so often gets rid of these sort of things...
Last week at a mates place I had spent a few days just tootling around his town and the Jeeperific wasn't happy at all, stop at lights and rough idle, so when we went back to our camp we went for a blast down the road and back, all good, might have been trying to do a burn, so a fast run seemed to do the trick and later looking at the data it seemed like the same time it did a burn .................

That makes sense then. I don't say I stay idle for a lot but I drive through heavy slow traffic every morning. It is a 35-minute drive to work and back during peak hours.

Can report my idle is still very smooth no roughness felt so far. But you are right it could be in the middle of a burn and it is just timing.

But I am glad that the system is clearing the check engine every time it thinks everything is okay so the system is doing its job no problem there.

I got to do some long runs this weekend so I am going to make sure I idle less and keep moving as long as possible.

Will see if I start fine and no CEL when I drive back home today.

[layback40]

Originally Posted by drover

If you have been toottling around, idling a fair bit, it may be just oil coating a sensor , so a good burn down the road if you can for 20 mins or so often gets rid of these sort of things...
Last week at a mates place I had spent a few days just tootling around his town and the Jeeperific wasn't happy at all, stop at lights and rough idle, so when we went back to our camp we went for a blast down the road and back, all good, might have been trying to do a burn, so a fast run seemed to do the trick and later looking at the data it seemed like the same time it did a burn .................

A good "Italian" tune fixes most things!

[vijith555]

Update on the situation:

So I have been driving around with multiple restarts and the CEL went away yesterday. This morning started her up (started smoothly) and the CEL came back on. Still drives great and fuel consumption response all good. So I drove to work. Decided to go see my local Auto Masters guy during lunch to see what his take is on this with the code in my hand so its easier for them. He told me its rare for this to come up on this Jeep but he is quite sure it's not the plastic gears that have failed but the sensor that sits inside the throttle body is failing. Giving out wrong readings which is causing an issue with the opening and closing plus throwing a CEL. He said if my plastic gears have already failed, I would have no throttle response and stall.

He is fully booked out and busy and said he will only have a chance in few weeks to book it in to have a full look (i did a walk in to see what I can verbally get out of him). He said keep driving it a bit and clear the codes to see if it comes back. I am going away overseas in a week or so and thought I will deal with this later on. As I got in the car and started her up, the CEL light went away this time. So it was able to clear the CEL itself too without me clearing it! I immediately ran into the store and told the mechanic this happened and he was like unless I cleared it, usually these codes only clear once the repair is done and someone clears the code. Even then it takes a few ignition cycles for it to clear.

So looks like this is a very early warning to my sensor failing or like Drover mentioned, it could be oil build up that needs to come off somehow either by driving or manual cleaning. Interesting to see if the CEL comes back up after a few ignition cycles. Worth the money having our scanning apps with us so we know what the CEL stands for and not need to buy 'anything' the mechanics tell you. Plus you know exactly what the problem is too.

[drover]

He is mistaking the butterfly valve as a throttle butterfly, it most certainly isn't, it opens and closes so the EGR system can operate it doesn't regulate speed or engine revs in normal operation like a carbie or old school diesels.....................

On CRD's the revs/speed is controlled by the amount of fuel injected into the engine, more fuel more suck, more air is drawn in, this butterfly valve is only there so when the ECU/PCM tells it to close up a bit the air intake is restricted so exhaust can be drawn into the combustion cycle, usuallly a very low revs/idle, when you increase revs the valve will open all the way so it gets full flow of clean air..................

It could be the temp sensor or the sensor in the box on the side which shows the valve position or a sticky gear........ ideally on the bench for a clean up and inspection, while the gearing is replacable I have only seen it at that one Italian site which must be okay as someone on here used it and never whinged that they were duds, the other stuff I would be shopping at a Mopar shop in the US I imagine, though Jeep here does surprise with prices at times.... Temp sensor is 68211210AA and is $316USD, the valve body is 68490035AA at $380-500 USD if in stock, scary stuff so go for a clean first....

I do believe if you removed the flap it would only throw codes that the EGR is faulty.............. if mine ever fails i will certainly being seeing first hand what happens when the flap is removed, the shaft will turn and the sensor will see its moved just some other sensor won't see a change in pressure so will have a hissy imagine.

[vijith555]

Originally Posted by drover

He is mistaking the butterfly valve as a throttle butterfly, it most certainly isn't, it opens and closes so the EGR system can operate it doesn't regulate speed or engine revs in normal operation like a carbie or old school diesels.....................

On CRD's the revs/speed is controlled by the amount of fuel injected into the engine, more fuel more suck, more air is drawn in, this butterfly valve is only there so when the ECU/PCM tells it to close up a bit the air intake is restricted so exhaust can be drawn into the combustion cycle, usuallly a very low revs/idle, when you increase revs the valve will open all the way so it gets full flow of clean air..................

It could be the temp sensor or the sensor in the box on the side which shows the valve position or a sticky gear........ ideally on the bench for a clean up and inspection, while the gearing is replacable I have only seen it at that one Italian site which must be okay as someone on here used it and never whinged that they were duds, the other stuff I would be shopping at a Mopar shop in the US I imagine, though Jeep here does surprise with prices at times.... Temp sensor is 68211210AA and is $316USD, the valve body is 68490035AA at $380-500 USD if in stock, scary stuff so go for a clean first....

I do believe if you removed the flap it would only throw codes that the EGR is faulty.............. if mine ever fails i will certainly being seeing first hand what happens when the flap is removed, the shaft will turn and the sensor will see its moved just some other sensor won't see a change in pressure so will have a hissy imagine.

I believe you are right and the mechanic was just giving me a generic answer to what he believed it was. I am hoping I won't need to replace those parts mentioned as they aren't on the cheap side plus would be painful to source if I need to.

The temp sensor you had on the image should be an easy one for me to check when I get a chance to open the cover up. I will first check that and reseat it (most likely won't do anything) but atleast it is a start.

Now going to see which start cycle I will get to see the CEL coming up.

[FARWEST]

Sourcing parts isnt that difficult...its the variations in the suppliers invoice thats tough to swallow.