Chrysler 300C & SRT8 Forums banner
1 - 14 of 14 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter · #1 ·
I am at a loss. I have a 2006 Chrysler 300c 5.7. RWD.
Not sure if this is coincidence or what but to take you from the beginning. My mom drives this car. She doesnt drive a lot so it tends to sit for several days between operation. It started with a weak battery. Car was jumped off many times. Couple days before Thanksgiving of 2018 the battery was replaced. I drove it to the gas station on Thanksgiving with no issues. About 5 miles. Put $30 worth of fuel. Approximately 9gals. It put the vehicle little over 3/4 of a tank. Started the car and it stalled. I assumed it was because of the fill (I know the fuel tank has the recall, just havent had the chance to take it in which is why I didnt fill it completely). On the way back to my parents the radio volume turned all the way down on it's own. Turned it up then it would drop again. Got home shut the car off, started it back up and radio was fine. Drove the car the next day and it began to stall randomly. Mainly when slowing down, coming to a stop, or while idling. Decided to bring the car to my house to diagnose further. The problem then began to get worse. It would try to stall at high speeds when the pedal was not being pushed (under load) or when the rpms reach an idle speed such as approaching a stop or turn. At that point it would stall. Had 2 codes. (Forgot the numbers) but lost communication to pcm and tcm malfunction.
So far I have replaced the pcm (no change), tcm (no change), throttle body (no change), plugs (no change), map (no change), front control module (no change). Both downstream o2 sensors (readings were strange and considerably different from bank 1 to bank 2) The only thing that made any change was adding 1/2 at of trans fluid to the transmission. Everything stopped temporarily after that but then returned a couple days later. I purchased an aftermarket dipstick and according to the reading the level is good, fluid needs attention but with 168k miles I'm a bit reluctant to change fluid as I have experienced more issues after doing so.
The car now will not run at idle. I have to hold the throttle above 1k rpm to keep it running. If i do this for 15-20 min it will idle in it's own typically after that.
Throttle response is good. The power is there if it will drive. But keeping it running while trying to get it into gear can be a challenge once it stalls.
I assume it's a fuel or air (vacuum) issue since I can keep it running by holding the accelerator. But the downstream o2 sensors still have me a bit confused. The upstream show the alternating voltage like they should. The downstream hold more of a steady voltage unless I snap the throttle. The part I'm confused about is b2s2 will hold steady around .6v but b1s1 holds around .2v. I would assume these should be relatively equal. I have really begun to suspect the cat on the bank 2 side. But I'm also suspect of something electrical since this really seemed to start once the battery was replaced. Both the battery and alternator have been pulled and tested.
I believe the codes that have been set are generated because of the stalling. I am really at a loss at this point and feel like I've just been throwing parts at it. Any suggestions?
 

·
Premium Member
Joined
·
3,499 Posts
How many miles?

Get back with any current codes.

EGR valve sticking open, which would support your having "to hold the throttle above 1k rpm to keep it running", is a possibility.
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #4 ·
148k. I pulled the egr and it doesnt appear to be stuck in an open position. I used a carb cleaner and did not get fluid to leak through the port. No codes will set until the car stalls on its 3/4th time. Then it's the U0100 and P0700 codes. It seems those codes are because of the stall.
I have become suspect of the fuel pump and the secondary pump for the tank. My understanding is the regulator is in the pump. One thing I noticed is I can turn the key on, the pump runs but if I wait a min (literally 60 sec) and pull the fuel line off at the rail the residual pressure seems low. Like it leaks down. Not sure if this is normal or not.
I tested this because I can start the car and it will run for a couple minutes at idle without holding the throttle open. Then it will begin to stall and continue to stall. I know fuel pumps dont generate a lot of heat, especially in tank pumps, but is it possible a diaphramor internal O ring or something could be partially bad?
It's been confusing.
 

·
Administrator
Joined
·
13,066 Posts
Low fuel pressure at the injector rails can be caused by a partially blocked fuel line or a failing fuel pump. In this case the pump must be powered up. So if residual pressure is low then it may not be either of those conditions. What is the fuel pressure like when the pump is powered up?

U0100 = Lost of communication with the Powertrain Control Module (PCM)

P0700 = Fault detected in Transmission Control Module (TCM) by PCM

U0100 is troubling because it indicates a loss of PCM signals. Without a signal from the PCM the fuel pump doesn't know it needs to pump fuel. Also, the P0700 TCM loss of communication is a second indication that the PCM is not communicating and controling the system properly.

Have you experienced any weird dash gauge, light or warning light blinking or pulsing? Just curious as this is a condition brought about by loss of communication between the PCM and the Body Control Module (BCM) aka the Front Control Module (FCM). This activity circles back to the loss of communication and would indicate that the PCM communication faults may be the root of all the issues.
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #6 ·
A couple of strange electrical things have happened since the battery was replaced just before Thanksgiving. 1- the radio (aftermarket) turned down on it's own. 2- I rolled the passenger window down then rolled it back up. Once I released the button it rolled down again on it's own.
After both of these things happened I turned the car off then started it again and neither has happened again. This is what led me to replacing the pcm and the front control module.
Prior to replacing the battery the car had been jumped off several times. However nothing strange nor drivability issues began until the battery was actually replaced. I was suspect of a bad battery and had it tested. It passed all the tests. Suspect of the alternator (due to the old battery being jumped and the vehicle running with a weaker battery). It passed all the tests. This of course was an off the vehicle test at the auto parts store.
I have also taken the cover off the autoshut down relay and watched it until the vehicle stalled. The contact never broke prior to it stalling. So I havent been suspect of the ignition switch.
The vehicle will run for hours as long as the pedal is pressed. Doesnt have to be much. I can hold it at 1k rpm and it wont stumble or anything.
Only other strange reading I get is the difference in downstream 02 sensors that was mentioned above in n earlier post. Both those 02 sensors were replaced.
 

·
Premium Member
Joined
·
246 Posts
Yes I was thinking that the Vapor canister or something in the vapor system was the issue the electrical problems are most likely due to the stalling would be my guess.
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #9 ·
I've blocked off both the vapor purge line to the intake and blocked the pcv port at the intake. Still stalled.
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #10 ·
Well now I have installed a new fuel pump. However one thing was curious. When I removed the old pump and secondary pump the passenger side well was empty while the driver side was full. Should these be equal levels? There is only the 1 line which runs out of the passenger side that feeds the engine. Now that I have installed the new pump and sending unit I'm wondering if is should go fuel up to balance these sides out. Or will it even make a difference?
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #11 ·
Still at a loss on this car. At the point of trading it in. But wasnt able to, I owe too much. So I'm stuck with it and about to let it sit and rot away.
Car is still stalling and it has to be electrical somewhere. Can anyone tell me more about the Zener Diode (slot 33 rear fuse box). I cant find a schematic of what it controls.
I read up on how to test diodes and in the case of a zener diode it basically acts as a voltage regulator. The video I watched stated it should read between 5-7v when tested in one direction and infinite in the other direction using a multimeter on the diode setting. The one I have reads 4.8v which has me wondering if it's what has been causing the randomness of the stalling. Only code I get is u0100. And it happens after the 3rd time it stalls.The other 2 diodes read 6.0v each. I am really suspect of this zener diode, cant find the part online so I'm going to have to go to the dealer directly. And information is extremely limited online for this particular one for my car. Any feedback would be appreciated.
Thanks
 

·
Registered
Joined
·
1 Posts
Still at a loss on this car. At the point of trading it in. But wasnt able to, I owe too much. So I'm stuck with it and about to let it sit and rot away.
Car is still stalling and it has to be electrical somewhere. Can anyone tell me more about the Zener Diode (slot 33 rear fuse box). I cant find a schematic of what it controls.
I read up on how to test diodes and in the case of a zener diode it basically acts as a voltage regulator. The video I watched stated it should read between 5-7v when tested in one direction and infinite in the other direction using a multimeter on the diode setting. The one I have reads 4.8v which has me wondering if it's what has been causing the randomness of the stalling. Only code I get is u0100. And it happens after the 3rd time it stalls.The other 2 diodes read 6.0v each. I am really suspect of this zener diode, cant find the part online so I'm going to have to go to the dealer directly. And information is extremely limited online for this particular one for my car. Any feedback would be appreciated.
Thanks
Sounds like you have the fuel tank recall issue.
 

·
Registered
Joined
·
1 Posts
Still at a loss on this car. At the point of trading it in. But wasnt able to, I owe too much. So I'm stuck with it and about to let it sit and rot away.
Car is still stalling and it has to be electrical somewhere. Can anyone tell me more about the Zener Diode (slot 33 rear fuse box). I cant find a schematic of what it controls.
I read up on how to test diodes and in the case of a zener diode it basically acts as a voltage regulator. The video I watched stated it should read between 5-7v when tested in one direction and infinite in the other direction using a multimeter on the diode setting. The one I have reads 4.8v which has me wondering if it's what has been causing the randomness of the stalling. Only code I get is u0100. And it happens after the 3rd time it stalls.The other 2 diodes read 6.0v each. I am really suspect of this zener diode, cant find the part online so I'm going to have to go to the dealer directly. And information is extremely limited online for this particular one for my car. Any feedback would be appreciated.
Thanks
Hey Tbone,

how's the diagnosis going. Sounds like you have done a pretty comprehensive list of diagnosis to no avail and i feel for ya. Started to read your thread as I have a good friend whose 300 just started stalling intermittently on her and asked for some advise. lots of people say the fuel tank issue but then a lot of people still seem to have the problem afterwards and so I'm not convinced. does the fuel tank have a regular cap on it? if so can i suggest having the cap removed and still seeing if the vehicle still stalls? Had a vehicle once where the cap stoped allowing the fuel tank to breathe and would stall it at idle. if that doesnt work, installing a fuel pressure guage on the rail and monitoring it may be the go?
 
1 - 14 of 14 Posts
Top