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Ignition shutting off 6-9 seconds after car is started?

ac1760ac1760 Posts: 10
edited January 2015 in Jeep
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!!

Comments

  • thecardoc3thecardoc3 Posts: 5,091
    Frustrated? You should try making a living actually diagnosing and fixing exactly these kinds of problems.

    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.
  • ac1760ac1760 Posts: 10
    edited January 2015
    Thank you so much for your response @cardoc3!! I will print this out for the tech guys that will be looking at this tomorrow. To answer your questions. Everything still works. The radio stays on, the heater etc. When it dies there is no sputtering etc. is like someone just turned the key off. We have tried reviving the RPM's up, putting in gear, but it continues to shut off. The only thing that pops up in the dash is service 4 wheel drive. I thought maybe the new ignition would buy me time until Jeep got the recall part made and available. I have even used the spare key, just in case the other key was going bad and the security system was shutting it off. I didn't realize that I should have put 89 octane in as fuel so I filled up the tank with 93 to raise the level that was left in the tank. All crazy ideas, but I feel like I am grasping at straws.
  • ac1760ac1760 Posts: 10
    @cardoc3 Sorry to comment to you again, I reread your post. I did take it to the Jeep dealer and they ran some tests they said to come up with the diagnosis that it was the ignition switch. Now what test I do not know. I plan on calling tomorrow and asking. I also called the Chrysler recall hotline and they have all the information that has been happening to the car. They suggested that I take it to another dealership to have it diagnosed. Now I think I have answered all your questions. Hope to hear from you again, if my answers help with more ideas.
  • thecardoc3thecardoc3 Posts: 5,091
    edited January 2015
    "They suggested that I take it to another dealership to have it diagnosed"

    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.
  • ac1760ac1760 Posts: 10
    @thecardoc3 Sorry to both you again, I thought I had figured out the problem. I thought it might have been related to the security system. You see, if I used the remote to lock and unlock the doors and then start the car it seemed to stay started. This was also true when I locked and unlock the doors using the key, but I had to take the key out after locking and reinsert the key to unlock and it would start. It seemed to not start without locking and unlocking the doors. I tested this about 5 or 6 times. I was so excited because I had thought I had solved the mystery. I had my husband come out and watch the process. Well, funny(not) thing, my little "trick" didn't work when I showed him!! Any thoughts on the security system possibly being the problem?
    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.
  • ac1760ac1760 Posts: 10
    @cardoc3 Then I definitely appreciate your time that you have put into answering my questions. When I get the car back, with a solution(hopefully), I will share the results. Thank you again.
  • ac1760ac1760 Posts: 10
    @cardoc3 This is what my local Jeep dealer said after working on it for 2 1/2 days. They even replaced the coils, to no avail.

    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.
  • ac1760ac1760 Posts: 10
    @cardoc3 they are replacing the TCM.
  • thecardoc3thecardoc3 Posts: 5,091
    Did they say why they are replacing the TCM? The P0882, TCM input power low is a code that I would really be keying on. When looking at a schematic the power inputs that the TCM measures its input power supply come from the TCM control relay in the power distribution center. It has dual inputs to the TCM on pins 28 and 38 of C4 (connector #4) The code criteria is that the voltage on those two pins is less than 3v when the module is commanding the relay on. Then we have the rest of the code descriptions which are rationality codes for different pressure switches and a sensor. P0869 P0846 P0871 P0988 The first thing to realize is they ultimately get their power from the same relay circuit that is setting the P0882 but they all have unique inputs to the TCM.

    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.
  • thecardoc3thecardoc3 Posts: 5,091
    C2202 Original Vin Mismatch or missing vin. This is the ABS control module looking at its own stored VIN information and comparing it to the VIN that it read in the vehicle communication data. It means that the information in its own memory is either wrong or missing. When there are system power problems, all bets are off on exactly what codes the different modules will generate. A trouble code doesn't tell someone what part is bad, it tells you what test failed. At this point we have one module the TCM with multiple inputs that are failing their tests for low system voltage, and we have a completely different module that forgets the identification number of the car its installed in. That isn't a coincidence at this point, it is screaming a drop in system voltage is occurring. We also have another piece of information from you, the car stalls. Now is it losing spark, fuel, or both? If the PCM is also losing system power like someone shut the key off, it would make perfect sense that no trouble code would be found, wouldn't it?

    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?
  • ac1760ac1760 Posts: 10
    @thecardoc3 I don't know what tests they did, I wish I did! I know my local dealership read your email and followed your suggestions, as well as other tests. They thought it might be the TCM, but was not convinced replacing the TCM would fix it. So at that point, I took it back to CarMax a week ago on Wednesday with the codes that I posted on here. They sent it over to the dealership they work with, with the info on the codes. They didn't look at it until this past Monday. I don't think they even did any more diagnostics work, I think they just looked at the paper from the other dealership and said sure let's replace the TCM. I just picked it up tonight, things seemed okay, but now I am concerned again! What can should/can I do? What should I be looking for now? I got them to extend my warranty for another 30 days, but if it doesn't show signs of anything I can't have them do anything. Any additional help/suggestions would be appreciated again!
  • thecardoc3thecardoc3 Posts: 5,091
    The problem is random, we know that. Full testing to prove what is happening hasn't occurred. As I have described numerous times the techs don't get paid to investigate problems that thoroughly so when one does it is unpaid time. Is (was) the TCM the culprit? Now that it has been replaced the only way we will know that it didn't fix it is if/when it acts up again. If it doesn't act up many might use that as proof of the repair, meanwhile you are still left concerned that it simply hasn't re-occurred yet and don't know if you can trust the car.

    Classic Scenario.
  • ac1760ac1760 Posts: 10
    edited January 2015
    @thecardoc3 I total understand what you're saying about the dealership not paying their mechanics to solve/resolve the problem. I do have to say though, that my local dealership put in above 5 hours to come up with what they did, under the one diagnosis fee. They even replaced the coils under that fee. Long story why they had extra coils for a 5.7 Hemi laying around the shop, but they put them in to check if they were the problem; again no additional fee. If I were to take your recent note suggestions to the dealer, can they still test for the other possible issues?
  • thecardoc3thecardoc3 Posts: 5,091
    There is nothing to test except for during the failure (symptom event), that is the only time that measurements can be made that provide clear results. If the TCM did in fact fix the problem, there will be no symptom to even provide a starting point.
  • ac1760ac1760 Posts: 10
    @thecardoc3 Thank you for all your time and effort. Your answer is what I thought. Let's just hope that the problem is fixed! I guess if the problem shows up again, then I will start with your notes and keep digging. Thanks again!
  • Hi @ac1760
    I have the exact same issue with my jeep commander. Did replacing the TCM solve the problem?
  • CasteloCastelo BrazilPosts: 1
    Please, I need your help ,I have the same 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.
  • Amged123Amged123 LibyaPosts: 1
    please tell us the results 
  • Bigtex48433Bigtex48433 Posts: 1
    I have this exact issue on my 2006 commander. Does anyone have the fix?
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