Trainmaster
New Member
- Joined
- Jul 4, 2019
- Messages
- 26
- Reaction score
- 10
The overflow nipple on the 3.7 coolant reservoir broke and flooded my engine bay. A few months after the repair, I was getting a P0304 #4 misfire with a P2311 code for a bad coil. I removed the coil and found it wet. It was shorting out for quite awhile. So I replaced the coil and plug and dried things out.
The miss didn't go away. Still a #4 miss and coil code. I moved the new coil and plug to another cylinder but the miss didn't follow it. Still a miss on #4.
I checked continuity on the two leads to the #4 coil. One lead is always hot (+12) when the ignition is on. The other should pulsate a ground from the PCM (computer's) #3 pin on its second-from-rear connector. There was no pulsating ground on that wire, though there was conductivity between the computer and the coil connector. I also checked each wire to ground and found nothing shorting to ground.
The PCM Computer on my 2005 has part number 56044576AO. The "AO" is just a date code and doesn't matter. It obviously lost its #4 coil output from being shorted so long.
Ebay has several sellers who will furnish a new PCM programmed to your VIN and mileage. I ordered one and got the wrong part number sent to me. Lots of these guys sell garbage. Sent it back and ordered one from a different dealer (Shifting Gears Auto on ebay) for $129. Plugged in the new computer and the truck runs flawlessly.
Just wanted to share this experience and hope it can help others.
The miss didn't go away. Still a #4 miss and coil code. I moved the new coil and plug to another cylinder but the miss didn't follow it. Still a miss on #4.
I checked continuity on the two leads to the #4 coil. One lead is always hot (+12) when the ignition is on. The other should pulsate a ground from the PCM (computer's) #3 pin on its second-from-rear connector. There was no pulsating ground on that wire, though there was conductivity between the computer and the coil connector. I also checked each wire to ground and found nothing shorting to ground.
The PCM Computer on my 2005 has part number 56044576AO. The "AO" is just a date code and doesn't matter. It obviously lost its #4 coil output from being shorted so long.
Ebay has several sellers who will furnish a new PCM programmed to your VIN and mileage. I ordered one and got the wrong part number sent to me. Lots of these guys sell garbage. Sent it back and ordered one from a different dealer (Shifting Gears Auto on ebay) for $129. Plugged in the new computer and the truck runs flawlessly.
Just wanted to share this experience and hope it can help others.
Last edited:
