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Engine stoped once after lifting my foot off the brake. Started right away. A few minutes later stopped while at high speed. It took 10 min of trying to start. Check engine light on, but my reader showed MIL off, no codes. Worked fine for 2 weeks (MIL turned off), then it stopped again and did not start for a few hours, when it was cold. MIL on. No codes. Autozone reader got P0351, P0352, P0353. At the end of scan MIL turned off. I will replace the coil pack, cause it's cheap. What else can it be? How can I check the ECM? Thank you!
What makes this problem better or worse?
Engine runs ok when it does, or not at all
How long has your 1996 Dodge Grand Caravan had this problem?
weeks
1 Reply
Hello, Start by testing the ignition coil. It should be able to provide a spark that jumps to your test light. For examples, youtube testing an ignition coil. Very easy. Those codes are typically an ignition coil issue, but you are right to question the ECM as well. Fouled spark plugs and bad plug wires can causes these issues too, especially if the plug wires are damaged by heat or friction. You can also check that the wire harness (low voltage, not plug wires) is serviceable. You could do this by moving the wires around to see if you can get it to stall while idling, plus inspecting for damage/cracks/oil soaking, etc. If the coils and wires pass their tests, let me know, and I'll look up the pin numbers to check at the ECM.
Thank you for your advice, I really appreciate it! Right now the engine runs perfectly. I checked the wiring and the low voltage connector is the only connector in this vehicle that looked perfect :) I have a cheap WIFI OBDII scanner. In the past i was able to read all sorts of parameters, like coolant temp, RPM, O2 sensor parameters etc. When the engine stoped and the Check engine light came on, my scanner could not read anything other than the voltage and type of protocol. It would even say the check engine light is off. After checking the wiring today, I connected the scanner and once again it red all the parameters, but it displayed VIN error. It found the error codes I wrote in my original post and cleared them. After that I started the engine again and I cannot read any parameters again. It's like the computer is not there. Again, the engine keeps on working perfectly. Other symptoms? The windshield wipers comes on when there is high vibration, like driving through a dip or slapping the car with my hand (old problem). Also it kills the solid state radiator fan relay, about once a year (maybe it needs new fans?). I don't think these are related. Come to think of it, the engine did stop before, after a transmission rebuild, when switching into reverse. But it started right up. I am tending to scratch the coil pack as a suspect since I don't have the rough idle, backfiring or lack of power at any time. Your thoughts would be appreciated!
Ok, that makes sense, you do need to test the ECM. Lack of communication with the ECM from the OBD port can be because of lack of power to the PCM (main relay, fuse, damaged wiring), or the PCM could have in internal error. You will want to pick up the service manual for the vehicle, or use something like alldataDIY.com for the testing procedure, as there are many steps involved. The biggest thing is to ensure it is powered and grounded, and you want to shake the wire harness around it while testing, as you may have an intermittent short or open.