Replaced spark plugs, nothing but problems.

[boogerhook]

2019 Ram 3.6 Big Horn 4x4

I preface this with, my battery died very abruptly after a 30 minute drive to a friend's house a few days ago.


Alright, at one point in time, I was a rather competent mechanic. I wasn't intimidated in the slightest at replacing my plugs.

I jumped the truck, with a CEL and it was stuck in first gear. I drove back and parked while I borrowed a vehicle to fetch a battery. Once replaced, it ran great no issues, but had a CEL I didn't care to scan for with no additional symptoms.

I'm at 110k and decided to not delay my 100k maintenance items any more.

Yanked the upper manifold, moved the harness and vacuum connections out of the way and replaced my plugs. Mopar matching part numbers for the same plugs I removed.

I reassembled the manifold, connected all disconnected connectors and hoses.

Truck started right up and idles fine with a slew of lights, but this wasn't terribly alarming after the battery issue. Test drove through the neighborhood with extreme reduced power. Idles smooth and starts normal, but feels like 90% of engine capability is just gone. Will still shift to second, unlike the issue when my battery died.

After clearing a bunch of codes I'm stuck with P0108 (MAP high output), a P0123 (pedal position circuit A high input) and P0222 (pedal position circuit B low input.

Any idea where to start? Online resources are limited, at least on 2 separate search engines I use.

With a pin out diagram and/or flow chart for diag I'll figure it out eventually but can't seem to find anything for mine specifically.

This seems oddly timed, and oddly specific to happen while replacing spark plugs.

Would disconnecting a sensor while the battery is still connected cause a sensor to fail?

I remember thinking I could swing it without disconnecting the entire harness. I had disconnected a few sensors, got to the point I felt I needed to disconnect the large, lever actuated connectors at the computer in the engine bay. I know better than to disconnect those with the battery hot.

Prior to first start after reassembly, when I reconnected the negative cable, there was quite an audible (and visual) pop as the terminal made contact.

Has anyone experienced this?

Should I just replace the map and pedal position sensor?

Any guidance would be appreciated.

Thank you.

 

[1BADRAMLIMITED]

2019 Ram 3.6 Big Horn 4x4

I preface this with, my battery died very abruptly after a 30 minute drive to a friend's house a few days ago.


Alright, at one point in time, I was a rather competent mechanic. I wasn't intimidated in the slightest at replacing my plugs.

I jumped the truck, with a CEL and it was stuck in first gear. I drove back and parked while I borrowed a vehicle to fetch a battery. Once replaced, it ran great no issues, but had a CEL I didn't care to scan for with no additional symptoms.

I'm at 110k and decided to not delay my 100k maintenance items any more.

Yanked the upper manifold, moved the harness and vacuum connections out of the way and replaced my plugs. Mopar matching part numbers for the same plugs I removed.

I reassembled the manifold, connected all disconnected connectors and hoses.

Truck started right up and idles fine with a slew of lights, but this wasn't terribly alarming after the battery issue. Test drove through the neighborhood with extreme reduced power. Idles smooth and starts normal, but feels like 90% of engine capability is just gone. Will still shift to second, unlike the issue when my battery died.

After clearing a bunch of codes I'm stuck with P0108 (MAP high output), a P0123 (pedal position circuit A high input) and P0222 (pedal position circuit B low input.

Any idea where to start? Online resources are limited, at least on 2 separate search engines I use.

With a pin out diagram and/or flow chart for diag I'll figure it out eventually but can't seem to find anything for mine specifically.

This seems oddly timed, and oddly specific to happen while replacing spark plugs.

Would disconnecting a sensor while the battery is still connected cause a sensor to fail?

I remember thinking I could swing it without disconnecting the entire harness. I had disconnected a few sensors, got to the point I felt I needed to disconnect the large, lever actuated connectors at the computer in the engine bay. I know better than to disconnect those with the battery hot.

Prior to first start after reassembly, when I reconnected the negative cable, there was quite an audible (and visual) pop as the terminal made contact.

Has anyone experienced this?

Should I just replace the map and pedal position sensor?

Any guidance would be appreciated.

Thank you.

i have no useful suggestions but sounds like a nightmare and hope its a easy fix for you.

im doing my plugs soon on my 5.7 non ET hope i dont run into any issues like this

 

[boogerhook]

i have no useful suggestions but sounds like a nightmare and hope its a easy fix for you.

im doing my plugs soon on my 5.7 non ET hope i dont run into any issues like this

Thanks man.

I haven't been completely stumped on anything in a long time. I've always been able to find a pin out chart, a loose connector or a YouTube video. But I'm completely stuck short of just arbitrarily replacing parts. Up until now I've taken great pride in accurate diagnosis and part replacement. Might have to roll the dice a few times on this one.

If I have any recommendations for you, disconnect your battery negative absolutely first.

Get a torque wrench for your intake bolts and spark plugs. A small inch/lbs one may be ideal depending on torque parameters for the intake. Tighten in the correct order.

Be very careful and diligent with disconnecting electrical connectors correctly, and also don't yank/be rough on the dumb little tie downs that secure your wiring. Often, they're stronger than connectors and wires.

 

[HSKR R/T]

I'd start by double checking you have everything connected properly, including vacuum lines.

Possibly have throttle body not connected, or something on firewall got knocked loose for the pedal position errors. Make sure no wires for pinched in intake manifold when you re-installed it

 

[boogerhook]

I'd start by double checking you have everything connected properly, including vacuum lines.

Possibly have throttle body not connected, or something on firewall got knocked loose for the pedal position errors. Make sure no wires for pinched in intake manifold when you re-installed it

I took today away from it to start with fresh eyes tomorrow. I did a quick double check, but tomorrow I'll be dissecting it.

Not happy about the possibility of doing it all again.

 

[Jako]

Wishing you well.

 

[Richard320]

I'd look for a cracked, plugged, or pinched line to the MAP sensor for that code.

The pedal position sensor is probably the one that started it all. It's inside, under the dash, on the pedal.

Before you start replacing parts, double check that you didn't leave a ground connection loose on the engine somewhere.

 

[boogerhook]

I'd look for a cracked, plugged, or pinched line to the MAP sensor for that code.

The pedal position sensor is probably the one that started it all. It's inside, under the dash, on the pedal.

Before you start replacing parts, double check that you didn't leave a ground connection loose on the engine somewhere.

That's on the agenda for today.

There were only 2 vac lines I disconnected. Both had the quick connect fittings and are in their places. There were no grounds disconnected. Only the harness connectors on that side of the engine bay, which are all reconnected.

 

[Rick3478]

I jumped the truck, with a CEL and it was stuck in first gear. I drove back and parked while I borrowed a vehicle to fetch a battery. Once replaced, it ran great no issues, but had a CEL I didn't care to scan for with no additional symptoms.

I'm at 110k and decided to not delay my 100k maintenance items any more.

Possibly a mistake. I'd have wanted to clear all existing problems before adding more. You could have blown something up by improper jump starting, so not a good idea to dump a bunch of new opportunities for error on top of it.

Would disconnecting a sensor while the battery is still connected cause a sensor to fail?

Probably not, but it might damage the ECU which is still powered.

Prior to first start after reassembly, when I reconnected the negative cable, there was quite an audible (and visual) pop as the terminal made contact.

That's not unusual. The truck has a lot of electronics with internal capacitors that have discharged while disconnected. There will be a significant inrush of current when you reconnect. It's critical that everything be properly grounded when you make that connection.

But something possibly significant that you didn't mention is the battery sensor. It also needs to be disconnected, and the order you do things matters.

 

[boogerhook]

Possibly a mistake. I'd have wanted to clear all existing problems before adding more. You could have blown something up by improper jump starting, so not a good idea to dump a bunch of new opportunities for error on top of it.



Probably not, but it might damage the ECU which is still powered.



That's not unusual. The truck has a lot of electronics with internal capacitors that have discharged while disconnected. There will be a significant inrush of current when you reconnect. It's critical that everything be properly grounded when you make that connection.

But something possibly significant that you didn't mention is the battery sensor. It also needs to be disconnected, and the order you do things matters.

If jumping a vehicle the way I've always done is improper on this vehicle, ram engineers can go f themselves.

I didn't have a scanner on me, nor as a sane person would I care while only replacing a battery, having done so many times.

What is a battery sensor, where is it and why is it important to disconnect?

If one can't swap a battery without specific instructions, then I give up.

 

[boogerhook]

Ended up being a loose map harness wire. Seems fixed for now. Unfamiliar with this style innova scanner, so still shows permanent dtcs, but no check engine light or symptoms and no PCM specific dtcs

We'll see how it shakes out.

Thanks guys.

 

[1BADRAMLIMITED]

Ended up being a loose map harness wire. Seems fixed for now. Unfamiliar with this style innova scanner, so still shows permanent dtcs, but no check engine light or symptoms and no PCM specific dtcs

We'll see how it shakes out.

Thanks guys.

Best of luck hopefully in a drive it’ll correct or fix itself and you’ll be good to go!