Transmission relay jittering 96 dodge ram 1500 5.2
#1
10-26-2019, 01:36 PM
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Transmission relay jittering 96 dodge ram 1500 5.2
My truck has had an intermittent starting issue for a few months now. Previously I was able to leave the key in the run position for about 10 mins and then the truck would fire right up. Recently it's been taking much longer than that to get it to fire up. I've noticed that the GEN light on the dash flashes with trans relay about 20 or 30 times in a few seconds then the truck will start right up after leaving the key in the run position for a few hours. I've replaced the relay and the ignition switch which hasn't help the issue. And I've checked the wiring harness, fuses and the pig tails going into the pcm for damage and havent found anything.
#3
10-26-2019, 10:17 PM
Positively assuming for now that it's not an issue with the PCM itself, the other possibility is an issue with power to the PDC or inside the PDC itself. Interestingly the transmission control relay, the auto shutdown relay and the fuel pump relay all get coil power via the same wire from the ignition switch (BTW fuse 9 in the inside fuse block is between the switch and the relays). The PCM then grounds the relay coils as it sees fit. The GEN light is solely controlled by the PCM, but the generator field coil gets power via the load side of the ASD relay so that's probably how the PCM monitors the generator. What I'm trying to say that's all somehow intertwined.
Check all the relays, you could pull the relays all together and one by one and see if anything changes with the flashing/clicking. The truck won't start though.
Make sure there is proper "clean" power to the relay coils (pin 86 on the relays). Possibly there is corrosion inside/under the PDC.
Check all the relays, you could pull the relays all together and one by one and see if anything changes with the flashing/clicking. The truck won't start though.
Make sure there is proper "clean" power to the relay coils (pin 86 on the relays). Possibly there is corrosion inside/under the PDC.
#4
10-27-2019, 10:10 AM
Check the battery terminals for a good connection first. When you first turn the key to "on"(not start/crank) do you hear the fuel pump prime the system? Try the key dance it will tell you if the pcm is working or at least getting power and it will let you know is it sees any issues.
http://dodgeram.info/Engine-Gas/OBDI/pcm_fault_code.htm
http://dodgeram.info/Engine-Gas/OBDI/pcm_fault_code.htm