Symptoms:
When key is in the on position everything works besides the Voltage and Gas gauge.
Scan tool will not communicate
Fuel Pump wont prime
I get C code AA (PCM message not received)
Sometimes for no reason at all I'll go out turn the key, the voltage and gas gauge work the fuel pump primes and the truck starts right up, I'll get communication on my scanner and I get absolutely no codes other than the C code AA
When that happens I'll drive down the street and it seems fine, other than hesitation shifting gears.
I originally thought it was the fuel pump so I replaced it, no change. Then I replaced the crankshaft position sensor... still no change. I checked all fuses and relays everything was fine. But one day I decided to charge the battery up while installed and I also took out the PCM to visually check it and the wires as well. Didn't see anything wrong reinstalled it battery got fully charged, I went and flipped the key and everything worked and truck started right up. That was the first time it started and ever since then it's been random works one day doesn't the next, so I got a new battery, started every time for about a week and then went back to random.
What could this be? I'm at a loss. I thought maybe it was the PCM.. but wouldn't make since for it to run fine sometimes and others not at all.
When key is in the on position everything works besides the Voltage and Gas gauge.
Scan tool will not communicate
Fuel Pump wont prime
I get C code AA (PCM message not received)
Sometimes for no reason at all I'll go out turn the key, the voltage and gas gauge work the fuel pump primes and the truck starts right up, I'll get communication on my scanner and I get absolutely no codes other than the C code AA
When that happens I'll drive down the street and it seems fine, other than hesitation shifting gears.
I originally thought it was the fuel pump so I replaced it, no change. Then I replaced the crankshaft position sensor... still no change. I checked all fuses and relays everything was fine. But one day I decided to charge the battery up while installed and I also took out the PCM to visually check it and the wires as well. Didn't see anything wrong reinstalled it battery got fully charged, I went and flipped the key and everything worked and truck started right up. That was the first time it started and ever since then it's been random works one day doesn't the next, so I got a new battery, started every time for about a week and then went back to random.
What could this be? I'm at a loss. I thought maybe it was the PCM.. but wouldn't make since for it to run fine sometimes and others not at all.
Nov 24, 2020 at 9:54 AM
