My 07 JKU Sahara is possessed

CBDugger

New Member
Joined
Oct 16, 2024
Messages
8
Location
San Antonio, Texas
The complete saga. Long story, so buckle up.

Bought the Jeep in May 2018. At some point a couple years later, it died while sitting at a Stop sign. It restarted and had no more problems. Until this summer. It died at two Stop signs in a row.

A few days later, it started dying when we hit a bump. Big bump, little bump, it didn’t matter.

When it died, it was ONLY the ignition that went out. All other power was still working. Dash, radio, accessory plugs. When it died, a bit more than half the time it would restart on its own. Before I could even react, it restarted. Later, it would restart when I pumped the throttle.

Then I accidentally drained the battery. After a jump start, I drove it the 4 and a half miles to my mechanic. I trust them. They are honest. However, it did not die one single time on that bumpy drive.

After a few days, they could not get it to die while driving. Period. So, I had the battery replaced.

I drove it as normal for a couple weeks with no problems. Then, when I drove it, it would start dying on bumps, but only after about 20 minutes of driving.

Then I had to take a short road trip. 2 hours one way. By the time I got to my destination, it was dying on about half the bumps. Half way back and it went bonkers. Ignition off and on very quickly, Dash lights Christmas tree-ing. Died. As I coasted on the highway shoulder, I put it in Neutral and it restarted.

Now the check engine light was on. Had not been before. But, the last 60 miles of the drive were perfectly normal behavior.

Got home and ordered a cheapy scanner to use with my phone. Better than no scanner. It said the crankshaft position sensor was bad.

I replaced it. $30 bucks and 10 minutes.

On a test drive, I got ¾ of a mile before it died on a bump. Restarted and turned around.

Here is where it gets weird.

Pulled into the driveway across from mine so I could back in. It died. And would not start. The starter would not disengage as the engine would not fire. Or, at least, it wouldn’t fire more than just to barely sputter.

After 20 minutes or so, I got it started. When I touched the gas pedal while in Reverse, it died. 10 more minutes and I got it started. Since everything is on a hill where I live, I let it roll back into my driveway and only put it in Reverse when the tires hit the concrete. A little gas and it died but I had enough momentum to get past the sidewalk.

A week or so later, a friend came over with his Xtool scanner. This is where we learned that it would only start if there was a person in both front seats. And, if one of them lifted up or got out, it would die. I have this on video.

The scanner reported that the crankshaft position sensor and the camshaft position sensor were not in sync. He used the scanner to fix that.

There are no other problems that I can see on the report he emailed me. There is something about a seat squib (?) not signaling, and possibly a rear seat sensor not signaling. I don’t know how to read these things. I am not a mechanic.

So, I loaded 150 pound of garden bricks in the passenger seat. It started right up. I rolled it down to the sidewalk, then reversed back up to my spot on the driveway. It died. And would not restart. That was a Sunday.

I let it set, battery connected, all week long. Sunday comes around again. This past Sunday. I go out and take the bricks out of the passenger seat. It will not start. I even tried to start it while sitting in the passenger seat. Nope.

So I unplugged all 3 plugs under the passenger seat. It started! But only in Neutral. Not in Park. Several times. In a row.

I needed to swap the positions of my 2 vehicles, so I put it in drive and pulled out and parked in front of the house. When I went to move it back, of course it died in Reverse. But, on the 2nd or 3rd try, it did go backward about 20 feet. And then it died. I just rolled it back to the curb.

Today, Wednesday. 3 days later. Not 8 days like the last time, but 3. I thought I would try it again as now I have some workday empty driveways I can pull into and just roll backward out of, to turn the thing around.

The battery is so low it doesn’t want to power the locks and the dash lights are very dim. Of course, it doesn’t even turn over.

An hour or so later, when I get home from an errand, I put the battery charger on it. It reads 14.1 volts. Than MAY be the charger output, but previously I always got the battery voltage. I could have read it wrong.

An hour or so later, I go out. 13.6 volts. It starts right up, in Park, first try. It flutters a bit like it isn’t going to start, but it did. In Reverse, 20 feet, died. So I restarted it and drove into a driveway, coasted backward, and drove into my driveway. No problems.

Possessed. Or bad ECM. Or a wire is shorting.

Info: I never drive the Jeep off road. I don’t generally speed and never drive over 75 in the Jeep. No mods except a winch, and it is disconnected. I am overweight, but I don’t even weight 300 pounds. I get the oil changed on schedule always. No wrecks while I have owned it. And I have the Xtool report if anybody wants to see it. Also, I have a lot of this on video for proof.

Any thoughts?
 
Welcome! That's a whopper of a first post, glad I was in the mood for some bedtime reading material. 😂

Sounds like you may have a bad ground. There are many threads on here where that has been the culprit. The bump triggered events would be consistent with this.
 
First thought was a wire rubbed bare. Second was a loose ground. I have tapped, hit, and jiggled every wire and connector I can get to under the hood and all the way back under the Jeep. None of them made it stall. Problem is that there are probably 4,374 grounds on this thing. I can find 3. Saw something about checking the grounds in the cab, but I don't have time til this weekend.
 
Do you still have the junk Factory battery clamps on? If so replace them with some HD clamps, also run a ground from the neg post to the alternator to give the engine better grounding.

You beat me to it! :ROFLMAO:

OP, Before you replace them, give them a solid twist to see if they are actually tight on the post, or just tight on the clamp.
 
Best advice I can give: call this guy-

1729176111321.jpeg


Not sure he's still in the biz after Linda Blair gave him such a hard time, but worth a try.
 
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Sounds super frustrating! I had a similar issue once and it turned out to be a loose connection in the fuse box. Might be worth checking all your fuses and connections? Just a thought!
 
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Reactions: CBDugger
Sounds super frustrating! I had a similar issue once and it turned out to be a loose connection in the fuse box. Might be worth checking all your fuses and connections? Just a thought!

Pulled the TIPM and cleaned the contacts and cleaned the blade fuses. The relays and bigger fuses I didn't want to mess with.
 
One diagnostic, and simple, is to get it idling if you can. If the wiring is original, the insulation may be getting brittle. You need it in neutral with the drive wheels off the ground so it can't go anywhere accidentally. Starting wiggling wires, which simulates bumps in the road, one wire at a time. A bad ground can be from cracked insulation or a broken wire that provides intermittent contact. If the engine repeatedly stalls when you move a specific wire, look into replacing that.
 
One diagnostic, and simple, is to get it idling if you can. If the wiring is original, the insulation may be getting brittle. You need it in neutral with the drive wheels off the ground so it can't go anywhere accidentally. Starting wiggling wires, which simulates bumps in the road, one wire at a time. A bad ground can be from cracked insulation or a broken wire that provides intermittent contact. If the engine repeatedly stalls when you move a specific wire, look into replacing that.

I would probably end up wound around the driveshaft. And I did this with it idling in Park.
 
The complete saga. Long story, so buckle up.

Bought the Jeep in May 2018. At some point a couple years later, it died while sitting at a Stop sign. It restarted and had no more problems. Until this summer. It died at two Stop signs in a row.

A few days later, it started dying when we hit a bump. Big bump, little bump, it didn’t matter.

When it died, it was ONLY the ignition that went out. All other power was still working. Dash, radio, accessory plugs. When it died, a bit more than half the time it would restart on its own. Before I could even react, it restarted. Later, it would restart when I pumped the throttle.

Then I accidentally drained the battery. After a jump start, I drove it the 4 and a half miles to my mechanic. I trust them. They are honest. However, it did not die one single time on that bumpy drive.

After a few days, they could not get it to die while driving. Period. So, I had the battery replaced.

I drove it as normal for a couple weeks with no problems. Then, when I drove it, it would start dying on bumps, but only after about 20 minutes of driving.

Then I had to take a short road trip. 2 hours one way. By the time I got to my destination, it was dying on about half the bumps. Half way back and it went bonkers. Ignition off and on very quickly, Dash lights Christmas tree-ing. Died. As I coasted on the highway shoulder, I put it in Neutral and it restarted.

Now the check engine light was on. Had not been before. But, the last 60 miles of the drive were perfectly normal behavior.

Got home and ordered a cheapy scanner to use with my phone. Better than no scanner. It said the crankshaft position sensor was bad.

I replaced it. $30 bucks and 10 minutes.

On a test drive, I got ¾ of a mile before it died on a bump. Restarted and turned around.

Here is where it gets weird.

Pulled into the driveway across from mine so I could back in. It died. And would not start. The starter would not disengage as the engine would not fire. Or, at least, it wouldn’t fire more than just to barely sputter.

After 20 minutes or so, I got it started. When I touched the gas pedal while in Reverse, it died. 10 more minutes and I got it started. Since everything is on a hill where I live, I let it roll back into my driveway and only put it in Reverse when the tires hit the concrete. A little gas and it died but I had enough momentum to get past the sidewalk.

A week or so later, a friend came over with his Xtool scanner. This is where we learned that it would only start if there was a person in both front seats. And, if one of them lifted up or got out, it would die. I have this on video.

The scanner reported that the crankshaft position sensor and the camshaft position sensor were not in sync. He used the scanner to fix that.

There are no other problems that I can see on the report he emailed me. There is something about a seat squib (?) not signaling, and possibly a rear seat sensor not signaling. I don’t know how to read these things. I am not a mechanic.

So, I loaded 150 pound of garden bricks in the passenger seat. It started right up. I rolled it down to the sidewalk, then reversed back up to my spot on the driveway. It died. And would not restart. That was a Sunday.

I let it set, battery connected, all week long. Sunday comes around again. This past Sunday. I go out and take the bricks out of the passenger seat. It will not start. I even tried to start it while sitting in the passenger seat. Nope.

So I unplugged all 3 plugs under the passenger seat. It started! But only in Neutral. Not in Park. Several times. In a row.

I needed to swap the positions of my 2 vehicles, so I put it in drive and pulled out and parked in front of the house. When I went to move it back, of course it died in Reverse. But, on the 2nd or 3rd try, it did go backward about 20 feet. And then it died. I just rolled it back to the curb.

Today, Wednesday. 3 days later. Not 8 days like the last time, but 3. I thought I would try it again as now I have some workday empty driveways I can pull into and just roll backward out of, to turn the thing around.

The battery is so low it doesn’t want to power the locks and the dash lights are very dim. Of course, it doesn’t even turn over.

An hour or so later, when I get home from an errand, I put the battery charger on it. It reads 14.1 volts. Than MAY be the charger output, but previously I always got the battery voltage. I could have read it wrong.

An hour or so later, I go out. 13.6 volts. It starts right up, in Park, first try. It flutters a bit like it isn’t going to start, but it did. In Reverse, 20 feet, died. So I restarted it and drove into a driveway, coasted backward, and drove into my driveway. No problems.

Possessed. Or bad ECM. Or a wire is shorting.

Info: I never drive the Jeep off road. I don’t generally speed and never drive over 75 in the Jeep. No mods except a winch, and it is disconnected. I am overweight, but I don’t even weight 300 pounds. I get the oil changed on schedule always. No wrecks while I have owned it. And I have the Xtool report if anybody wants to see it. Also, I have a lot of this on video for proof.

Any thoughts?

Update: Found the gear selector shaft plastic dust cover had broken. Checked inside the console. Nothing of note. It started. It did not die when I gave it gas in Reverse. I even put the transfer case in Neutral so I wouldn't be fighting the brakes. No dying. Drove it around the block. First half was great. Ran fine. Then it died. Thought about something so I tested it. It died a second time on demand. When I suddenly let go the throttle. Started and drove it down to the house, didn't die. Pulled in a neighbor's drive way to turn around, coasted back to cross the street, put it Reverse and gave it gas. Guess what happened? Rolled up into the OTHER neighbor's driveway and that is where it stayed. It would not fire. Just spinning the engine. I could smell fuel and the scanner was showing 13-14% fuel pressure. It was acting just like a flooded carb. It does not have a carb. Eventually ran the battery down so I put the charge on it (next door neighbor), and made a ground wire to run along side the existing one from the ECM (or whatever that 4 plugged plate is). Attached it to cleaned contact, and unplugged and replugged the 4 plugs. By this time, the battery was charged. Man did that thing start quick! Drove the 75 feet from driveway to driveway just perfect. Didn't line it up right, so I restarted it. BOOM, right away. I DID go ahead and add a ground from the battery to the alternator brace. Have not tried it since. I want it to get completely cold. If I have accidently fixed this, I am gonna scream.
 
The complete saga. Long story, so buckle up.

Bought the Jeep in May 2018. At some point a couple years later, it died while sitting at a Stop sign. It restarted and had no more problems. Until this summer. It died at two Stop signs in a row.

A few days later, it started dying when we hit a bump. Big bump, little bump, it didn’t matter.

When it died, it was ONLY the ignition that went out. All other power was still working. Dash, radio, accessory plugs. When it died, a bit more than half the time it would restart on its own. Before I could even react, it restarted. Later, it would restart when I pumped the throttle.

Then I accidentally drained the battery. After a jump start, I drove it the 4 and a half miles to my mechanic. I trust them. They are honest. However, it did not die one single time on that bumpy drive.

After a few days, they could not get it to die while driving. Period. So, I had the battery replaced.

I drove it as normal for a couple weeks with no problems. Then, when I drove it, it would start dying on bumps, but only after about 20 minutes of driving.

Then I had to take a short road trip. 2 hours one way. By the time I got to my destination, it was dying on about half the bumps. Half way back and it went bonkers. Ignition off and on very quickly, Dash lights Christmas tree-ing. Died. As I coasted on the highway shoulder, I put it in Neutral and it restarted.

Now the check engine light was on. Had not been before. But, the last 60 miles of the drive were perfectly normal behavior.

Got home and ordered a cheapy scanner to use with my phone. Better than no scanner. It said the crankshaft position sensor was bad.

I replaced it. $30 bucks and 10 minutes.

On a test drive, I got ¾ of a mile before it died on a bump. Restarted and turned around.

Here is where it gets weird.

Pulled into the driveway across from mine so I could back in. It died. And would not start. The starter would not disengage as the engine would not fire. Or, at least, it wouldn’t fire more than just to barely sputter.

After 20 minutes or so, I got it started. When I touched the gas pedal while in Reverse, it died. 10 more minutes and I got it started. Since everything is on a hill where I live, I let it roll back into my driveway and only put it in Reverse when the tires hit the concrete. A little gas and it died but I had enough momentum to get past the sidewalk.

A week or so later, a friend came over with his Xtool scanner. This is where we learned that it would only start if there was a person in both front seats. And, if one of them lifted up or got out, it would die. I have this on video.

The scanner reported that the crankshaft position sensor and the camshaft position sensor were not in sync. He used the scanner to fix that.

There are no other problems that I can see on the report he emailed me. There is something about a seat squib (?) not signaling, and possibly a rear seat sensor not signaling. I don’t know how to read these things. I am not a mechanic.

So, I loaded 150 pound of garden bricks in the passenger seat. It started right up. I rolled it down to the sidewalk, then reversed back up to my spot on the driveway. It died. And would not restart. That was a Sunday.

I let it set, battery connected, all week long. Sunday comes around again. This past Sunday. I go out and take the bricks out of the passenger seat. It will not start. I even tried to start it while sitting in the passenger seat. Nope.

So I unplugged all 3 plugs under the passenger seat. It started! But only in Neutral. Not in Park. Several times. In a row.

I needed to swap the positions of my 2 vehicles, so I put it in drive and pulled out and parked in front of the house. When I went to move it back, of course it died in Reverse. But, on the 2nd or 3rd try, it did go backward about 20 feet. And then it died. I just rolled it back to the curb.

Today, Wednesday. 3 days later. Not 8 days like the last time, but 3. I thought I would try it again as now I have some workday empty driveways I can pull into and just roll backward out of, to turn the thing around.

The battery is so low it doesn’t want to power the locks and the dash lights are very dim. Of course, it doesn’t even turn over.

An hour or so later, when I get home from an errand, I put the battery charger on it. It reads 14.1 volts. Than MAY be the charger output, but previously I always got the battery voltage. I could have read it wrong.

An hour or so later, I go out. 13.6 volts. It starts right up, in Park, first try. It flutters a bit like it isn’t going to start, but it did. In Reverse, 20 feet, died. So I restarted it and drove into a driveway, coasted backward, and drove into my driveway. No problems.

Possessed. Or bad ECM. Or a wire is shorting.

Info: I never drive the Jeep off road. I don’t generally speed and never drive over 75 in the Jeep. No mods except a winch, and it is disconnected. I am overweight, but I don’t even weight 300 pounds. I get the oil changed on schedule always. No wrecks while I have owned it. And I have the Xtool report if anybody wants to see it. Also, I have a lot of this on video for proof.

Any thoughts?

More data:
It appears to malfunction only after reaching operating temp. Before thay, awesome. After that, it dies under throttle in Reverse, dies randomly when I hit a bump or let off the throttle. If I hit a bump AND let off the throttle, dies for sure. Then, it dies a final time and will not restart. Yesterday I let it cool off and it started fine. So, is this a drive-by-wire problem? Or is it a dirty throttle body?
 
More data:
It appears to malfunction only after reaching operating temp. Before thay, awesome. After that, it dies under throttle in Reverse, dies randomly when I hit a bump or let off the throttle. If I hit a bump AND let off the throttle, dies for sure. Then, it dies a final time and will not restart. Yesterday I let it cool off and it started fine. So, is this a drive-by-wire problem? Or is it a dirty throttle body?

Also, the red lightning bolt throttle control light came on when it died for the last time. I never get a throttle position error on the scanner.