2001 Dodge Grand Caravan 3.8 Liter intermittent no start
I have a customer who brought us in a 2001 Dodge Grand Caravan 3.8Liter. Customer states - intermittent no crank, no start. This vehicle was towed in as the customer stated he had issues getting it to start in cold/wet weather. So here's the run down. Scanned for codes initially and found a P0351, P0352, P0353, along with a P1684. Started by testing the battery and found a loose battery cable. This was corrected. Cleared codes and found that the vehicle intermittently wouldn't start. Connected a spark tester, and used my Power Probe 4 (setup in Injector Test Mode) to check for fuel injector pulse. Determined when the vehicle wouldn't start that I had fuel injector pulse but no spark. Then reviewed wiring diagrams and checked out the ASD relay and all applicable fuses. No issues found. Then checked my 5 volt reference off the MAP sensor. Found 5 volts steady, even when the no start occurred. Then determined my crank sensor pin location on the C1 connector of the PCM. Back probed PIN 32 to scope the crank sensor. Obtained a good known crank pattern off IATN and compared it to my scope pattern when I had a successful start. Picture perfect. Ever since, haven't had a crank no start. The customer is leaving the vehicle with us over the weekend and we want to test again Monday morning to see if we get a crank no start. My concern is that we corrected the no start by backprobing the PIN 32 (crank sensor at the PCM). I have tried to remove the backpin and jiggle the wire... still starts up every time. Does anyone have any suggestions on verifying that I corrected the issue by manipulating PIN 32 wire to the PCM (crank sensor).
Any help or guidance greatly appreciated. Thanks in advance.
Scan tool set and ready, look at any pids that are relevant for starting then move in with atm test or scope depending what we see or don't see in pids.
Did you test fuel volume and pressure at no start?
I have injector pulse but no spark, so I didnt proceed with volume or pressure tests.
Backprobing /should/ only "fix" the problem if the pin-fit is crappy. I would disconnect and pin-drag the connector for terminal tension.
I will try that monday. Any other suggestions on what to look for on an intermittent crank no start?
You have already ruled out all the normal things I think of for intermittent no-start, when you found that you had fuel injector pulse, but no-spark, except for the fuel pump. (which of course won't kill spark). Clear DTC first, then I'd want to watch cam and crank signal, spark control, and injector control. If the only thing missing of those four, is spark control, then the PCM is bad. Since
Hello, Avery I would attached a lab scope with an inductive ammeter to the ignition coil control circuit ran the engine and monitored the ignition coil primary amperage waveform to check for a short this will rule out any issues with the ignition coil P0351,P0352,P0352 which are all Primary/Secondary circuit faults. Also look for Corrosion in the fuse box its a know issue. Let me know what you
Excellent point, I will setup an inductive clamp in the morning... just hoping I get another crank no start so I can verify.
Update on this vehicle - and some additional information I should have stated from the beginning. This vehicle also had wipers that would just randomly come on, and a HVAC blower that run non stop. Both, the wipers and the blower were not able to be control from the switches. I ended up suspecting the Intelligent Power Module, and my suspicion was correct. This van, has the Front Control module