Long story short, I was having misfire issues. I replaced the crank and cam sensors which didn't change anything. I had a coolant leak from the quick connects out of the firewall for the heater core. That apparently damaged the ignition coil on cylinder 8. Replaced the coil and the engine ran great. However, now I have these codes and no AC.
P0452: Fuel Tank Pressure (FTP) Sensor Circuit Low Voltage
P0530: Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit
P0651: 5 Volt Reference 2 Circuit
From what I was told, all three of these are on the same circuit on the PCM and they require a 5V reference circuit which can get grounded out. Is there a fuse for this circuit that I could have blown? I tried to trace the wires from the AC pressure sensor but it just wires into the big harness on top of the intake. I briefly looked to see if anything was grounding out by the starter since it was kind of hanging down when I replaced the crank sensor and reinstalling the starter requires moving around some of the wires around the oil pan. I'm not really sure what I'm looking for there though. I also replaced the cam sensor without removing the intake and had my hands in and out of the harness back there. I ran a camera back there but couldn't see anything unusual.
I also unplugged the AC pressure sensor and after clearing the codes, that code didn't come up again. But I still have the P0452 and P0651 after doing that. Not exactly sure what that tells me though.
Anyone have any advice for me or could tell me how to trace the 5V reference circuit (or even rewire it)?
P0452: Fuel Tank Pressure (FTP) Sensor Circuit Low Voltage
P0530: Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit
P0651: 5 Volt Reference 2 Circuit
From what I was told, all three of these are on the same circuit on the PCM and they require a 5V reference circuit which can get grounded out. Is there a fuse for this circuit that I could have blown? I tried to trace the wires from the AC pressure sensor but it just wires into the big harness on top of the intake. I briefly looked to see if anything was grounding out by the starter since it was kind of hanging down when I replaced the crank sensor and reinstalling the starter requires moving around some of the wires around the oil pan. I'm not really sure what I'm looking for there though. I also replaced the cam sensor without removing the intake and had my hands in and out of the harness back there. I ran a camera back there but couldn't see anything unusual.
I also unplugged the AC pressure sensor and after clearing the codes, that code didn't come up again. But I still have the P0452 and P0651 after doing that. Not exactly sure what that tells me though.
Anyone have any advice for me or could tell me how to trace the 5V reference circuit (or even rewire it)?
