Engine/Transmission (1998.5 - 2002) It choked and died with no warning….can’t figure it out

[IndyBoy]

I’ll give as much detail as I can, any help would be greatly appreciated:

3 days ago I was on my way to get a new tool box for my home shop. I stopped at the first fuel station 2 miles from my home and filled up at the diesel bay, where there is no chance I put in the wrong fuel. I started up and took off, but only made it about 200 yards before it surged for a couple seconds and died. There was no warning and I was completely caught off guard. I checked the mirrors for a puke trail (because it sounded bad when it died) but the road was clean. Everything looked fine under the hood so the next think I did was, turned the ignition back on and kicked the starter to check lift pump pressure. (I have the AirDog set up, and a pressure gauge on my pillar. ) The lift pump didn’t turn on. Now, I assume that the lift pump never turned on when I left the fuel station, and I ran the 200 yards with the vp44 sucking what it could, dry.

Next step: get the lift pump running: its supply voltage was fine to the relay, but the computer wasn’t turning it on as it normally did (it plugs in to the stock lift pump harness. ) To get it running, I jumped the terminals in the relay connector, thus bypassing the computer. But this is a question to come back to: what would cause the computer to not turn on the lift pump?

I have since bled all 6 injector lines at the head with the hotwired lift pump, and it won’t so much as fire. With minutes of cranking (breaks in between cranks), still nothing.

Error codes:

P0122* Throttle Pos Sens Voltage Low

P1596 Speed Ctrl Switch Always Hi

P1693 DTC Detected in Companion JTEC Mod

I don’t know what to do with the last two, and basically assumed that they are not of significant issue. I followed the Chrysler diagnostics steps for p0122. I confirmed that I have adequate voltage coming from the ECM and that the wiring between the APPS and the ECM is fine. Which then the manual tells me to replace the APPS……The manual never actually tells me to test the apps, but this is what I then did: I checked the no throttle output voltage to the PCM on the firewall. It was . 43v. It was supposed to be . 54v according to the sticker on the APPS. Low, yes. . dead, no. I loosen its adjusters and rotate the sensor to get the voltage up. I was able to increase it to . 49v. Then I move the throttle while reading the output, and the voltage appears to be linearly increasing. So, replace the APPS still? Why? It seems to be working fine, it’s an analog potentiometer… The truck should be able to run, if its providing output near where it’s supposed to, which it is. Correct me if I am being thick skulled, but I think the manual was trying to get me to waste money.

This is about the extent of my story. So here I am with these 2 questions:

Why won’t it start, when fuel comes out of the injector lines, after having bled them all?

And again, what could have caused the computer to not turn on the lift pump? (I still have to jump the relay to get it to turn on)

The one last thing to mention, which is what is so bizarre, is: if the truck failed to turn the lift pump on…yet it kept running until it ran out of fuel (I think), why wont it start after bleeding the lines?

The alternate scenario, is that it surged and died all at once, and THAT is when the lift pump stopped working, not when I refueled. If this is the case, than it never actually ran the vp44 dry, and I think my ECM is shot. (but when I bled the lines, there wasn’t instantly fuel,,,, so I do think the lines were dry)



Any input would be appreciated,



Derek



p. s. I disconnected the edge comp, which did nothing.

 

[IndyBoy]

I should add this: My truck has 175,000 miles on it, and the VP44 has 20,000 on it since it was remanufatured and installed by a dodge dealer.

 

[JLandry]

So here I am with these 2 questions:

Why won’t it start, when fuel comes out of the injector lines, after having bled them all?

Derek,



If the VP44 is shot, fuel can still ooze out of the injector lines and the engine still won't start. Also, if enough air is still trapped in the high pressure injection lines the VP44 won't be able to fire the injectors.



Have you tried holding the accelerator pedal to the floor while cranking? That's the only way I've ever been able to get my engine to start after getting air in the injector lines (changing the injectors or the VP44) even though I bled them.

And again, what could have caused the computer to not turn on the lift pump?

It's not completely unheard of for the ECM to suddenly fail to energize the lift pump yet still function normally in every other way. I've read about that happening here on the forum at least a couple of times. I assume this is caused by a simple failure of some internal electronic components. The solution is to wire the lift pump relay to activate off some other circuit which is energized whenever the ignition switch is in the RUN and START position. This is less than ideal, but better than trying to find a old used ECM and it's FREE to do.



But before you resort to that, did you verify 12v from the ECM for the lift pump is NOT present when you bump the starter? You said verified 12v was present at the relay but the relay was not powering the lift pump. Did you rule out the relay isn't the culprit? They do fail.

The one last thing to mention, which is what is so bizarre, is: if the truck failed to turn the lift pump on…yet it kept running until it ran out of fuel (I think), why wont it start after bleeding the lines?

Not if the VP44 was ruined from being completely starved of fuel.



I would do this:



1. Have the ECM relearn the APPS range by turning on the ignition (don't start) then slowly push the accelerator pedal to the floor and slowly release it. Shut the ignition off.



2. Attempt to start the engine again while holding the accelerator to the floor.



3. If it still won't start, you can disconnect and hot wire the VP44 (search the forum for instructions) and try again. By hot wiring the VP44 you'll eliminate the ECM completely. If the engine starts and runs while hot wired but not when connected to the ECM, the that'll point to the ECM being the problem.



My feeling based on probabilities of failure is that the VP44 is toast. While ECM's do fail, it's pretty rare. And usually when that happens you'll have a bunch of other signs something is wrong like more diagnostic trouble codes and other strange behavior like no wait to start lamp.



Please keep us posted on your progress.



Good luck,



John L.

 

[IndyBoy]

I spoke with Tim at Timbo APPS to see if I should buy one of his APPS (TPS). He informed me that the truck should at least idle, even if the apps is disconnected. Then he suggested that I disconnect the VP44 connector, and hotwire it (pin 6= ground (top, closest to block), pin 7 = 12v bottom, closest to block) as it should idle this way (won't shut off with key either).
Sure enough it fired right up, ran rough till the remaining air got out of the injectors, but then sounded great! Thank you tim, when my APPS eventually goes, I'll come to you.
Sounds like ECM now… I'm going to see if there are more diagnostics tests I can run.

John: I did confirm that the ECU was NOT sending 12v to the lift relay when I bumped the starter. And I bench tested the relay, and its fine. At first, that's what I thought went out…. But I'm certain that's not the case now.
Since it runs with a hotwired VP44, I'm glad that I don't need to replace it. Soon as I reconnect the VP44 harness, it won't start again.
Is it for certain the ECM at this point? Or could it be the PCM? I don't really know where the control responsibilities are balanced.

 

[IndyBoy]

I checked the grounds and the fused 12v inputs on the harness that connects to the ECM. They checked out fine. Also, its pin #15 (or 16… I'm going off memory now) on that harness that runs the lift pump and I juiced it, and the lift pump turn on just as expected! So, now, I am almost certain that it is the ECM.
Does anyone have a spare that they could sell me at a reasonable cost?

 

[JLandry]

Is it for certain the ECM at this point? Or could it be the PCM? I don't really know where the control responsibilities are balanced.

The ECM plays a direct roll in controlling the VP44. The PCM plays an indirect roll through the ECM.



You'll need to do some additional trouble shooting before you can say the ECM is bad.



Try the following checks (in no particular order):



1. Verify the fuel injection pump relay (located in the PDC) is working properly by temporarily swapping it out with another known good relay. When the ignition key is in the RUN or START position, pin #7 of the VP44's multi-pin connector should have battery voltage. If it doesn't, either the ECM isn't energizing the relay or the relay isn't receiving power through 20A fuse #3 in the PDC.



2. Verify the ECM is receiving power on pins 48 and 50 of the ECM connector even when the ignition switch is OFF. This circuit is also fed by fuse #3 in the PDC (same as the VP44 relay).



3. Verify pins 30 and 49 of the ECM connector have a good connection to chassis ground.



4. Verify pin 5 of the ECM connector has battery voltage when the ignition switch is in the RUN or START positions. This is an ignition switched circuit that causes the ECM to wake up. This circuit is fed by a 10A fuse (#9) in the PDC.



5. If everything above checks out OK, try swapping out the ASD (Auto Shut Down) relay located in the PDC with another known good relay and see if the engine will start.



Did you check for trouble codes using a code scanner or just the ignition key / odometer window trick?



John L.

 

[IndyBoy]

Thanks again John, I'll run those tests and get back. I wont be able to get to it until Friday, but i'll get back to you on this thread.

 

[IndyBoy]

All these items checked out fine. I did learn one thing when reconnecting the ECM with the ignition on. The lift pump ran for half a second. It still wont start when I bump the key, but it was interesting that if the ignition is on, each time I cut and restore power to the ECM (by removing and reinstalling fuse #3) the lift pump bumps for a half second.
Is it safe to say now that my ECM is junk?

 

[IndyBoy]

when replacing the ECM, what do I need to know if i'm looking for a used one? do I have to get one from a 2000, or would a 98. 5-2002 work?

 

[JLandry]

Well I'm fresh out of ideas at this point.

Do you know anyone with another 24v 2nd gen that might let you temporarily try their ECM?

when replacing the ECM, what do I need to know if i'm looking for a used one? do I have to get one from a 2000, or would a 98. 5-2002 work?

Ideally you want an ECM from the same year truck and with the same transmission, but I believe you can get away with using any ECM from a 24v 2nd gen truck WITH THE SAME TRANSMISSION (auto vs. manual). Going from memory, the ECM's seem to be internally wired differently between the two different transmission types for the cruise control.

Important notes:

The ECM software is different for each year and emissions configuration, but the hardware (box) is the same. Once an ECM has been initially flashed for a particular year/configuration of truck, the software cannot be changed again (reflashed) to a completely different year/configuration using a Chrysler DRBIII. This is because the DRBIII checks the current software version and will only allow upgrades of that version software and not complete changes. This prevents potentially catastrophic mistakes by service techs when updating ECM software at a dealership.

If you do need a complete reflash of the software for an ECM when from a different year of truck, I believe Bob Wagner (smartypower.com) has the equipment to do that. He might even have a spare ECM to sell you.

Good luck,

John L.

 

[IndyBoy]

more info

I sent my ECM to Python injection to be bench checked,,, because my dodge dealer cant. They said it checked out fine and I should look into the Cam and Crank sensor.

The wiring checked out fine for both sensors so i ordered replacements.

I took out the Crank sensor, and found that it looked like 1/16th of an inch of the end of it had been ground off, and there were two little wires exposed... it looked like junk and I assumed that the end cap was adhered on, and it failed. I installed the new one, put the starter back on, and bumped it. . the lift pump turned on for 25 seconds, finally!



I fired up the truck and everything seemed to run fine. I went for a short 5 minute drive, and after a couple of minutes of operation i saw my tach skip a beat. a half minute later it skipped a beat again. the duration of the tach sitting at 0 rpm was increasing each time, untill it essentially stayed there. I now assumed that i will have only 25 seconds till the lift pump stops, since i'm sure there is no crank sensor input. After i got the truck back in my shop, i shut it off (assuming it would not start again) and i was right. It was dead.

This explains why i thought it ran dry on fuel when it broke down a few weeks ago,, because it did. the truck continues to run with the bad sensor, after 25 seconds the lift pump shuts off,,, and then the vp44 runs dry.



I disconnected the crank sensor connector to inspect the terminals, which were fine. For curiosity, I bumped the starter with it disconnected,,, and i was a little surprised, but the lift pump turned on. So i tried to start it, and it started. It couldn't idle very smooth, but it would run, and rev.



So, again i took out the crank sensor. The new sensor now also looked like some amount of the cap was ground off (but there were no internal workings exposed yet. (see pictures attached. the one on the left was the first one, the one on the right is the new, now not functioning one).



Has anyone ever heard of this???? Should I assume that that toothed ring that the crank sensor feeds off is bent, or there is something on the crank that is rubbing on the end of the sensor?

I've got the oil draining now, so i can look up the drain plug (which I just changed after i thought i confirmed i fixed the truck, but before it got goofy)



I used a mirror to look in the hole for the sensor,,, but i really couldn't tell anything.

 

[JLandry]

Has anyone ever heard of this???? Should I assume that that toothed ring that the crank sensor feeds off is bent, or there is something on the crank that is rubbing on the end of the sensor?



I used a mirror to look in the hole for the sensor,,, but i really couldn't tell anything.

Wow! Looks like you found the overall cause of the problem.



The camshaft position sensor takes it's measurements off the rear of the camshaft drive gear. I wonder if the camshaft has slid rearward due to excessive wear of the thrust plate located on the front of the engine?



John L.

 

[DavidC]

The crank has a wheel bolted to it with teeth that trigger the Crank sensor. I have heard of the wheel coming loose which could be your problem. The wheel is in 2 or 3 pieces and bolts to the crank. If this is the case you are going to have to remove the oil pan to inspect/repair. If the 2000 is like the 99 the cam sensor is for diagnostics only and has nothing to do with engine operation.



Dave

 

[IndyBoy]

Dave, you're on it.

After I let the oil drain out and stop dripping I laid under the truck for a while with a light inspecting the teeth on the the ring bolted to the crank that feeds the crank sensor. (I can never remember what that ring is called unless the manual is in front of me). I turned the engine over slowly via the front drive shaft with the truck in 6th gear 4x4 and 2 wheels jacked up.....

Anyhow that toothed ring should go around 360 and its supposed 2 pieces,,, one lager and one small, that are bolted to the crank. I learned that mine is broken. A piece about the size of the smaller piece of the ring was missing, but it looked like it was broken off, not just loosened and fallen off.
Either way, i'm pretty mad about this one and loosing faith in my truck.

So the good news is that I found the source. The bad news is that i have to take the oil pan off to fix this... .

per the repair manual to remove the oil pan:
1. disconnect battery
2. put truck on hoist
3. remove transmission and transfer case
... . step three is what makes me mad about this one. It will be a bit till i get time to take out the transmission so i can slide the oil pan out.

Has anyone ever heard of this? Seems like a pretty crappy design for a crank sensor.

Thanks everyone for your help...

 

[DavidC]

I agree with the crappy design. When the 53 cracked Cummins sent a 56 replacement to the local Cummins dealer to install. When they thought they were all done the truck had problems. They forgot to install the tone ring!!. They had the truck another week tearing it apart again. The shop foreman later told me they were thinking about doing away with the ring and using the cam sensor but decided to keep it the way it was built. Maybe they found out a different ECM would be required and who knows what else. I have heard only once until now of a tone ring failure. I have also read posts on here of some that have gotten the oil pan out with out doing what the manual states. You may try to dig up those posts and see if it is feasible for your situation. Have you priced/located a new ring yet?. I am curious how much they want for that glorious thing. Some one on here can check on prices and availability just can't remember the name. If I see it again I will let you know.



Dave

 

[DavidC]

Found it. The persons name is mwilson. When you find out if you need parts you may pm him and see what he knows. Good luck and let us know how it goes.



Dave

 

[IndyBoy]

thanks Dave... since you mentioned the 53 block. . I never bothered look until a few weeks ago if mine was one (didnt want to know)... but it is. I wonder if there is a stat for the % of 53s that cracked over total made... Even though we hear about it alot, i'd still assume it must be low... in the 5%ish range.

 

[DavidC]

thanks Dave... since you mentioned the 53 block. . I never bothered look until a few weeks ago if mine was one (didnt want to know)... but it is. I wonder if there is a stat for the % of 53s that cracked over total made... Even though we hear about it alot, i'd still assume it must be low... in the 5%ish range.

It would probably be pretty hard to come up with that number unless Cummins was tracking that and actually wanted to share the info. Doubt that black eye would ever get out. To my knowledge the 53 block made in Brazil was the problem as they missed a support in the casting process. Mine cracked while pulling a 5th wheel from Phoenix to Payson up some pretty steep grades which it had done many times before. It had finally had enough when it cracked. The bad part was mileage was 53300 and 3 months out of warranty. Chrysler would do nothing and Cummins offered a reduced price on replacement. Basically that engine cost me another 4k than I had already paid when I bought the truck new. A real sore point with me. All that happened in 2004 and I am still not over it especially with Chrysler.



Dave

 

[Road Dog]

Has anyone ever heard of this? Seems like a pretty crappy design for a crank sensor.

Not that I know anything about this but I came across this in my 2001 FSM (section 8i):
OPERATION - DIESEL
The Camshaft Position Sensor (CMP) performs
multiple functions. One function is to detect engine
speed (rpm). Another function is to relate crankshaft
position and Top Dead Center (TDC) of the number 1
cylinder. Because the CMP is now used to relate
crankshaft position, the Crankshaft Position Sen-
sor (CKP) is no longer used.

Maybe an '01 or '02 ECM will remove the need to fix the CKP. Unless there's no CMP in earlier engines.