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Ignition shutting off 6-9 seconds after car is started?
I bought a used 2006 Grand Cherokee with 53,000 miles. On the fourth day of ownership, I started it and it died about 5 or 6 seconds later. I tried again and it did the same thing two more times, then stayed running. Had no problems for about 24 hrs, then the starting and dying continued again. I took it back to the dealership, they said that they got 3 transmission codes off of the commuter. Did a flash reset and updates; did not fix the problem. I was told it was the ignition switch and there was a recall on that part, but there was no part yet to fix the problem. Great!!! So I suggested a new ignition switch, reluctantly they put one in. Got it back home, with 4 starts on the new ignition, it did it again!! Every time that I have had to start it, it has taken more cranks to finally keep it running. I find it very difficult to believe that I could have 2 bad ignitions in a row. Not impossible though, I know. Any thoughts or ideas on what else it could be, would be greatly appreciated. Very frustrated!!
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First, when it shuts off, does it sputter and die or is it like someone turned the ignition off?
What else stops working when it dies, anything? (power seats, power windows, radio????)
The trick to diagnosing these kinds of problems is to first identify the system, or systems affected.
We would have to find out if it is losing spark, losing fuel, or both.
The connections for the digital oscilloscope for the first test would be to the ASD relay command from the PCM. The ignition command for the cylinder #1 coil, the current for all of the coils. The injector #1 command and the current for all of the injectors. The crankshaft position sensor signal at the PCM, and the camshaft sensor signal at the PCM. System power(s) to the PCM should also be monitored during a failure event. (that's about 10-12 signals on average)
A tech would also at the same time need to monitor scan data for anomalies (temperature sensor readings, idle air control values, MAP/MAF etcetera ) as well as get a gage on this to measure the fuel pressure.
This approach would rapidly allow the stalling to be narrowed down to basically the input versus the output sides of the PCM. Based on the information gathered other testing points would then be chosen in order to try and drill down towards the exact cause.
I don't blame them for being reluctant to throw an ignition switch at this. When no real testing is done to prove where a failure originated the only thing that ever really get's proven is that the attempt didn't fix the car. The lack of future failures isn't really "proof" because many owners get left wondering if today will be the day that the car acts up again.
These can be solved with a disciplined approach and a good game plan. It does take some patience especially since once it starts and stays running you have run out of opportunity to make any more progress until the next event. (next day?) No-one can just off the cuff say what is causing the issue, you already have proof of that with the ignition switch. One other problem, its unlikely that the dealer has a technician that will willingly take the above approach. You see they don't pay their techs while they fight problems like this and the tech could tie up a good bit of time over several days in legitimately trying.
Think about what I wrote about the dealers not usually having a tech that is trained to do this kind of work, has the right equipment, and is willing to invest the time to take a disciplined approach and figure this out the first time. Since it shuts off like someone turned a switch off, that makes monitoring the primary inputs (cam and crank sensors) and the primary outputs (injector and ignition coil) as well as power to the PCM more important than some of the other things that also should be tested and proven. Many might throw a crank sensor at this, in practice I've proven more crank sensor harness connector (pig tail) failures than the sensors themselves when facing a similar symptom description as yours. But that doesn't mean that is what is wrong with your Jeep, again it has to be proven with the correct approach.
On another note, the car started and did not turn off both yesterday and this morning after sitting all night. Would that make you think to check one thing more than another? BTY I do not arm/lock my car at night. So, both mornings I got in the car and started it. Any other thoughts?? Dropped car off at dealer tonight.
This cannot be a security system issue. Any no-start associated to the security system generates codes in the SKIM/SKREEM, instrument cluster, RKE (remote keyless entry) and the PCM. The PCM has a Go / No-Go strategy and sets a code for a theft detected if it is commanded off and it sets a different code if it doesn't receive SKIM/SKREEM data and turns itself off. Your previous visit would have revealed the theft deterrent codes and the tech would have been investigating that part of the vehicle system.
On another note, the car started and did not turn off both yesterday and this morning after sitting all night. Would that make you think to check one thing more than another?
No, that only shows how difficult of a task catching the failure is really going to be. The car could be at the shop for a week and the tech not make any progress if it doesn't act up enough times to prove what is, as compared to what is not working when the engine stalls. Through the years fixing problems like this took many unpaid hours and quite often once the answer was in hand the tech is often told something along the lines of "well if you knew what you were doing you would have looked there first". Your getting a little glimpse of what it takes to diagnose a lot of vehicle issues. There have been many times that someone uses a little information to try and prove a given issue like you have with the security system, that's really little more than a guess without real test data to support it. They will solve this, it is difficult work and demands a patient approach because one can only make progress when the problem is occurring. Remember, for the tech that actually takes this on and solves the problem it is likely thankless, unpaid time. Meanwhile there will be others who are doing coolant flushes, injector services and other similar services that are doing quite well for themselves.
BROUGHT IN HER 2006 JEEP GRAND CHEROKEE with 53,280 MILES WITH IT STALLING OUT AT STRT UP CODES IN SYSTEM TCM PO882 TCM POWER INPUT LOW,PO869,PO846,PO871, PO988,. WE REPROGRAMED FOR MISMATCH ECU W/SKIM, DID NOT TAKE CODE B1A28, TESTED ALL COIL PAKS AND BATTERY AND CONNECTIONS, OTHER CODES IN SYSTEM U0100 FCM LOST COMM W/PCM, U0100 ASB LOST COMM. W/PCM, U1414 ORC MISSING CONFIG DATA, C2202 VIN MISMATCH/MISSING. WE THINK MY BE PCM FAILURE.
Any thoughts with all these codes??? Thanks in advance.
They are P0869 Line Pressure High, which means that the signal voltage was lower than the PCM would accept as a valid signal. An open in the 5v reference would be one plausible cause, but I'm going to refer back to the low system voltage code. If the power to the TCM was low, then it makes perfect sense that the 5V reference to the pressure sensor, and therefore the return signal would be low.
P0846 2C pressure switch rationality, P0871 OD pressure switch rationality and P0988 4C pressure switch rationality. Depending on what gear the computer has selected, certain solenoids would be turned on to move valves in the valve body and when those valves move fluid under pressure would be directed to the different clutches. These pressure switches return a voltage signal to the TCM so that it can tell if the solenoids in fact pressurized those clutch packs. The only thing common to all three of those switches is the power supply to them and of course the TCM. That all comes down to one problematic answer. All of those codes will logically set if there is a loss of 12v power to the TCM through the TCM control relay.
Now lets look at the other codes that were reported. U0100 FCM LOST COMM W/PCM, U0100 ABS LOST COMM. W/PCM, U1414 ORC MISSING CONFIG DATA, C2202 VIN MISMATCH/MISSING
You have codes where critical modules lost communication, one of the most common reasons for a module to be missing on the data bus is a loss of power to it. Are you noticing a pattern here?
I'll add more detail in the next response.
At this point I'd have to study some schematics and choose some strategic testing points power supply feeds for the modules that are showing a loss of communication and of course the relay for the TCM and watch them with my digital scope during a failure event.
I'm not convinced the TCM is the answer.......
How did they come to this conclusion? Exactly what testing efforts and data went into confirming that the TCM had power to it when it coded for not having it?
Classic Scenario.
I have the exact same issue with my jeep commander. Did replacing the TCM solve the problem?
I did all the tests that you requested the other user, and they were all within the parameters that you had informed.
I also changed the TCM module for a new one, but the result was the same.
It has been 3 days running OK, but on the 4th day the "Service 4wd" comes on the screen, and the engine shuts off.
I hope you have been able to fix the user's car AC1760.