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

[vijith555]

Originally Posted by TR Laredo

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?

Mine is the original OEM one. Original FOB too. I have the factory spec sheet mentioning the remote start package too.

Never had issues with the remote start works flawlessly. Only mentioned it here as I wanted to point out when using remote start, the system takes its time before it cranks, much like the manual two step process I am doing to test this theory

[vijith555]

Originally Posted by 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...

This was my thinking before trying this method. I thought if I gave the system an extra couple of seconds and then crank it might have a better chance and to my surprise it did. The cranking time itself is not a problem, only the seconds before it actually starts cranking is what is variable on my car. But as mentioned I did start her without waiting accidentally yesterday and seemed to start fine (it was constantly starting bad for the last 3 weeks prior to yesterday). So not sure if the MAF clean has helped too.

The battery is just about a year old. Replaced it last year. Did not test it recently.

[vijith555]

So far the delayed start process of first pressing the starter button twice without foot on brake, waiting for another 2-3 seconds and foot on brake start has been working. No CELs pop up this way and no shudders or chokes too just like before. So I can definitely tell some sort of timing issue is going on here otherwise the supposedly 'broken' throttle body cannot behave perfect just by doing this. Could be a sensor affecting the ECU/PCM that is throwing the sequence off by a few seconds.

Knowing this I started researching online to see if there are any similar instances of this. And I found out a forum where so many 2021 GC owners faced an issue similar. They don't get any error codes but the car would not start sometimes going into infinity crank and usually start on second try. Mine is not like this unless I try to restart it too soon when on a CEL lit up time. And they all mentioned when they use remote start using the fob, it starts perfectly. So this explains the timing I was talking about. And all these cars were taken to dealerships with multiple components swapped for example fuel pumps and other related stuff but they still cannot figure out.

I am inclined to getting the battery and charging tested next week just to rule that out. Could be a load issue like if the starter kicks in a few seconds before another component is loading up, it probably under powers something causing this who knows? And my error code relates to electronics. And by giving it that few seconds manually, or by using remote start (as it does the delayed start by design) it is helping just enough to get the car started without leaving an error.

Going back in time I just remembered only a few days after getting the P02E8 code on dash, I noticed the PRND lights on my gear shifter lit up and not turning off after turning off the car. I had a post about it and with your suggestion the battery disconnect fixed the PRND issue. I am thinking this could be an indication of maybe the computer being upset about something, power related or totally not related.

Going to ring Jeeps R Us on Monday and tell the fantastic bloke who has been so helpful over the phone about my findings. He remembers me now as soon as I ring him too. Hopefully he might shed some light on this after hearing all this. I am lucky he offers any sort of advise/help over the phone because most garages here are just arrogant unfortunately.

[LeCheese]

On our previous 2011 we had the issue where it would crank but not fire - the issue ended up being the WIN (wireless ignition node) module, which essentially detects the key and tells the vehicle all is good to start the engine.

The behaviour was more inconsistent than your issue, so doubt it's the same problem, but the thread's here if you wanted to have a look:
http://www.ausjeepoffroad.com/forum/...d.php?t=129837

[drover]

With this other extra info, more thoughts come to the surface .............

If at the first start of the day you put foot on brake and it does a bit of a longer than normal crank before firing, the ambient temp is in the 20's then this could point to a fuel pressure problem, where your having a bit of bleed back and the LP pump has to prime/purge the lines first before the starter fires up.... have a look underneath and see if the fuel filter housing, the base of it is dry... On cold days the glow plug will delay start as it heats up while the lines are primed, when temp reached usually 10-15 sec at most then starter fires up.... but long cranking is a sure sign of air in line and long cranking is a big No, No in any CRD it will destroy your HP fuel pump in short order.....

The starter should only fire when the ECU has done all its checks and responses from numerous systems tick all the boxes... some systems though do not throw codes but may cause other unit fails which will throw a code, thats why all info regarding faults should be noted as the fault that appears unrelated can actually be the pointer to what the fault is ........... the main reason places just swap out units till the fault goes away, saves them time, not so your wallet..

Remove the OBD dongle for a few days ......

[vijith555]

Originally Posted by drover

With this other extra info, more thoughts come to the surface .............

If at the first start of the day you put foot on brake and it does a bit of a longer than normal crank before firing, the ambient temp is in the 20's then this could point to a fuel pressure problem, where your having a bit of bleed back and the LP pump has to prime/purge the lines first before the starter fires up.... have a look underneath and see if the fuel filter housing, the base of it is dry... On cold days the glow plug will delay start as it heats up while the lines are primed, when temp reached usually 10-15 sec at most then starter fires up.... but long cranking is a sure sign of air in line and long cranking is a big No, No in any CRD it will destroy your HP fuel pump in short order.....

The starter should only fire when the ECU has done all its checks and responses from numerous systems tick all the boxes... some systems though do not throw codes but may cause other unit fails which will throw a code, thats why all info regarding faults should be noted as the fault that appears unrelated can actually be the pointer to what the fault is ........... the main reason places just swap out units till the fault goes away, saves them time, not so your wallet..

Remove the OBD dongle for a few days ......

Thank you for pointing in some directions here and yes I am collecting all evidence so that if it comes to someone doing a full diagnostics one day..i am giving them all info so it saves their time and my wallet.

Coming to the starter regardless of whether I delay the starter or not my starts are always quick and fires up. Never struggles starting unless it is on a CEL stuck mode and I turn off engine and immediately try to restart it which is something we will not do normally.

Only thing I am fixing/avoiding is getting a CEL if I do the delayed 'ON' position and start. Even when on a bad start the starter cranks and starts the car quick but only thing you notice is half a second after the engine comes to life there is a choke from the throttle flap as it closed fully (which should not happen on normal starts evidence my videos)

I am thinking you are on a point here by asking me to remove that OBD that is plugged in all the time now. It is one of the good ones that supposedly goes to sleep after 20 minutes of no activity and engine shut but yes it is another thing added to the load in the morning.

I have never seen the starter taking 10-20 seconds of heating before it cranks. It is probably never that cold here in WA. The longest time it would have taken to crank would be like 5 seconds.

My not long cranks but the ones followed by a slight choke is because of the throttle flap choking air when it closes it to much due to some confusion on the first second of starting. Which seems to be avoided on delayed starts as the throttle flap behaves correctly then. If I hadn't taken videos of it I would have never known these things. If you see my last video the cranks you see and hear are the ones I get always. They are the same as a year ago.

[vijith555]

Originally Posted by LeCheese

On our previous 2011 we had the issue where it would crank but not fire - the issue ended up being the WIN (wireless ignition node) module, which essentially detects the key and tells the vehicle all is good to start the engine.

The behaviour was more inconsistent than your issue, so doubt it's the same problem, but the thread's here if you wanted to have a look:
http://www.ausjeepoffroad.com/forum/...d.php?t=129837

This is interesting almost made me feel like it is the remote start module you are mentioning. Mine never fails to start. Just the slight choke right after starting which drops the revs down and the car just recovers in half a second without stalling. It is like someone covering the air to the car with their palm for half a second and opening it. Ofcourse caused by the throttle flap behaving wrong in mine due to some other things going around. But the delayed start has proven the flap works correctly.