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

[Jeeper6]

When I was in Perth a few months ago I bought a water pump from these guys...https://www.jeepspares.com.au/

Yes they are out in Canning Vale at 2/9 Sorbonne Crescent. I was holed up at my brothers place at Warwick at the time...being a Sandgroper vijith555 you'd know distances anyway.

I'd contacted them when I was in Kalgoorlie when looking for a pump, they seemed ok to deal with. They offered me an option of a "genuine" pump or an after market at the time...I noted they do have a workshop on site where they play with Jeeps.

I have no idea if they are any good as all I did was buy a water pump...

[vijith555]

Originally Posted by Jeeper6

When I was in Perth a few months ago I bought a water pump from these guys...https://www.jeepspares.com.au/

Yes they are out in Canning Vale at 2/9 Sorbonne Crescent. I was holed up at my brothers place at Warwick at the time...being a Sandgroper vijith555 you'd know distances anyway.

I'd contacted them when I was in Kalgoorlie when looking for a pump, they seemed ok to deal with. They offered me an option of a "genuine" pump or an after market at the time...I noted they do have a workshop on site where they play with Jeeps.

I have no idea if they are any good as all I did was buy a water pump...

Spoke to these guys just now and they said they have none at the moment and a new one from eastern states which they can order in would be around $1600. That sounds way to steep. The genuine MOPAR ones on ebay are $1200. He did say that it is so damn rare the throttle bodies on these go and only had like 1 a year or something. And when I said 2018 he was like wtf no way.

He did suggest that before I go ahead with any replacement, it is worth getting the car run for diagnostics at a Jeep dealership (I know this is what we all are trying to avoid). He reckons their readers can read a bit more info sometimes and also they could give a definite answer instead of guess work.

I am thinking of attempting another MAF clean. I suspect my MAF could be slightly off creating this issue. I did try to clean it last time but the two mesh plates on either side of just dont let you spray the damn thing properly. Did you guys know of a way to remove either one of those protection grilles before spraying it?

[vijith555]

Alright I have another update from our P02E8 world.

So I think I have found out how I can start the car without the throttle choking the engine. This is something I noticed way before all these began to be honest. So what I knew from before was that when you get in the car and put your foot on the brake and push the starter, the time it takes for the engine to crank after the electronics showing up on cluster varies. Some days it takes like about a couple of seconds longer. So I always thought maybe it was something to do with ambient temperature in the morning or the car just randomly took different times to crank. Some mornings when you push the starter it starts even before most of the lights on the instrument lights up. Never really cared because there were no problems. And when I use the remote starter, it always takes longer to start. You can see the car puts the start position to ON for a few seconds before it cranks on a remote start as it is programmed that way probably.

So what I have been doing since yesterday was starting the car by first cycling the button to 'ON', waiting for about 4-5 seconds and then putting my foot on brake and hitting the button to crank and believe me it cranks and starts with no choke/hesitation. And guess what just now after I have been starting this way the CEL cleared itself! This has not cleared itself for the past 3 weeks no matter how I drove it or started. But now I know how to start her this way and the car seems to be happy. Yes, it is pretty manual but this is another big clue into fixing this thing. I don't think a guy running diagnostics at a workshop can discover things like this because they don't spend this much time with the car. I dont think anything is really wrong with the throttle body to be honest. And it is not the fact that more fuel is coming into the engine by waiting longer because you will know when you read the rest of this post. It is some sensor or computer that is mucking up the startup sequence. It is definitely a timing issue. I almost always start the car in the mornings using remote start so it took a while for me to realise this issue as remote start takes longer before it cranks eliminating the issue.

Now to the more interesting part - So proving this method made the car happy, I took the hose off to the throttle body, placed my trusty phone in front and took another video clip of the flap behavior when I started her using this delayed two step method and guess what - the flap only flicks a tiny bit but not shut and open completely when cranking so the engine cranks and starts with nothing bothering it. And to my surprise when you turn the engine off, the flap just does a two-step close open and goes to open position almost immediately which means if I crank her up again without waiting, it would start without choking - not that I need to always. But I did find out on an earlier day when the CEL is cleared, the flap resets itself quick like this so you crank almost instantly without waiting. So the restart readiness is good when there are no CELs. And to have the car CEL free, just start her in two steps. So yes it is definitely driving the flap the way it should eliminating the issue. And maybe this delayed startup is required for the first start of the day which is missing now because it consistently starts immediately when the foot is on brake. Sometimes I honestly think because I did so many changes using JScan (only superficial light and door lock behaviors) weeks before this issue, maybe I have upset the computer in some way who knows. And it may need a reset again. Not battery disconnect but a proper reset perhaps?

Took the MAF out again and drenched that thing with some MAF cleaner again. Gave it a good dry and installed it back. I am suspecting just like the MAP, the MAF or another sensor is probably sending a bad signal to cause this confusion and the throttle body is held culprit in the end.

Here is the latest video and you can see how happy that throttle body works. Let me see if I can consistently keep it starting like this. My two step start process - feels like a car with an actual key. And when there is no CEL, I can just remote start without needing to do this method after sitting in the car because remote start consistently starts delayed and will help in this situation provided this method works consistently lol

https://1drv.ms/v/s!Ap_EJv8kfE9c1QLY...fwsvO?e=ZObFrj

[drover]

Did you give the temp sensor in the throttle body a good flush as well ...........

It all sounds kinda strange that you get cranking before the lights, have you had a battery load test done ??? you would be amazed how a battery that seems to be great can cause many gremlins....... age and voltage display mean nothing at all.

Then again if you leave the OBD dongle plugged in, some can cause things to go wobbly at times so I have heard ....

Of course you may have caused a conflict in the check list even by fiddling with something that seems to be not involved in engine start, things like just doors closed is part of the check list ....

[Jeeper6]

When starting mine from cold, I usually hit the start button without my foot on the brake for a couple of seconds anyway to ensure the fuel pump is pressurised...then foot on brake and start.
On some starts from cold it does crank a tad longer, the crank time does vary by milliseconds when hot or cold. I have never worried about it...last Jeep was the same.

As drover pointed out, the battery condition in these things is critical. Any voltage drop can cause all sorts of weird things to happen. That said, a 2018 shouldn't be having battery issues....but you never know...

[TR Laredo]

Originally Posted by vijith555

Alright I have another update from our P02E8 world.

And when I use the remote starter, it always takes longer to start. You can see the car puts the start position to ON for a few seconds before it cranks on a remote start as it is programmed that way probably.

https://1drv.ms/v/s!Ap_EJv8kfE9c1QLY...fwsvO?e=ZObFrj

Is your remote start key fob one of the originals supplied with the car or is it an aftermarket one without the Jeep logo on it?

[vijith555]

Originally Posted by drover

Did you give the temp sensor in the throttle body a good flush as well ...........

It all sounds kinda strange that you get cranking before the lights, have you had a battery load test done ??? you would be amazed how a battery that seems to be great can cause many gremlins....... age and voltage display mean nothing at all.

Then again if you leave the OBD dongle plugged in, some can cause things to go wobbly at times so I have heard ....

Of course you may have caused a conflict in the check list even by fiddling with something that seems to be not involved in engine start, things like just doors closed is part of the check list ....

No it does not crank before lights but cranks almost along with the lights coming on and some days lights come on, 2-3 seconds later the crank. So far I have a brand new MAP, and yesterday I actually gave the MAF sensor a damn good clean. I noticed my last attempt to clean it did not go well as I did not spray the hot wires properly. This time I sprayed it to look clean after I learnt where it is located. Yes I cleaned out the temp sensor on the throttle body till it shined like new. My eyes are on the MAF now. I have a suspision the readings from the MAF (even though not broken) are a bit off and the thorough clean is helping.

And I did accidentally start the car without the two-step process yesterday and she started normal without the shudder (meaning the throttle flap opened and closed correct). So maybe the MAF is also a part culprit and me cleaning it thoroughly has helped?

Before the MAF clean I was running JScan and taking air flow readings down. And to my surprise since the clean yesterday, those numbers are far different. The difference between the air flow rate measured vs air flow target coming from the Bosch HFM6 sensor readings have nearly tripled. It was less before the clean. See below pics.

Before MAF clean:


After MAF clean:



My battery is only a year old did not go into testing that again. And the reason I changed it last year was the car was telling me every few starts it is going into power save mode. (not sure if the 2018 ones can early detect) And when i took it to battery place, just as expected battery was no good it was the original. So now have a good high performance one in there.

After a few days of this starting process I am going to try starting the car normally without waiting and see how it goes. Something may have changed.