A/C Help - Throwing P1545 and P1546 codes - SOLVED
A/C Help - Throwing P1545 and P1546 codes - SOLVED A/C compressor froze up recently and killed the car. Drove a few times with no A/C with no issues. Had the compressor replaced on Monday at a local shop and compressor won't engage. Replaced the A/C relay, checked for codes, no dice, so I left from there with both myself and mechanic scratching our heads.
Looked into the tune and found that the tuner had disabled the following codes for A/C:
• DTC P0530 A/C Refrigerant Pressure Sensor Circuit Malfunction
• DTC P0531 A/C Refrigerant Pressure Sensor Circuit Range/Performance
• DTC P1539 A/C Clutch Status Circuit High Voltage
• DTC P1545 Air Conditioning (A/C) Clutch Relay Control Circuit
• DTC P1546 A/C Clutch Status Circuit Low Voltage
After starting the car and scanning, the following two codes appear:
• DTC P1545 Air Conditioning (A/C) Clutch Relay Control Circuit
• DTC P1546 A/C Clutch Status Circuit Low Voltage
If I clear the codes, P1545 appears without the AC being turned on, and I can make P1546 show up by commanding the AC clutch on from within HPTuners. Right now I'm at a loss, looking for help/suggestions. (WhiteBird00 - if you're looking at this, the car is a '98 TA, still on original PCM)
Two items of note:
1. While mechanic was trying to sort out the issue, I saw a huge spark while he was poking around near the compressor (not sure if that's helpful or not)
2. I brought the car to a local dealership for estimate recently, not sure if they did anything while the car was there, but just putting it out there.
Looked into the tune and found that the tuner had disabled the following codes for A/C:
• DTC P0530 A/C Refrigerant Pressure Sensor Circuit Malfunction
• DTC P0531 A/C Refrigerant Pressure Sensor Circuit Range/Performance
• DTC P1539 A/C Clutch Status Circuit High Voltage
• DTC P1545 Air Conditioning (A/C) Clutch Relay Control Circuit
• DTC P1546 A/C Clutch Status Circuit Low Voltage
After starting the car and scanning, the following two codes appear:
• DTC P1545 Air Conditioning (A/C) Clutch Relay Control Circuit
• DTC P1546 A/C Clutch Status Circuit Low Voltage
If I clear the codes, P1545 appears without the AC being turned on, and I can make P1546 show up by commanding the AC clutch on from within HPTuners. Right now I'm at a loss, looking for help/suggestions. (WhiteBird00 - if you're looking at this, the car is a '98 TA, still on original PCM)
Two items of note:
1. While mechanic was trying to sort out the issue, I saw a huge spark while he was poking around near the compressor (not sure if that's helpful or not)
2. I brought the car to a local dealership for estimate recently, not sure if they did anything while the car was there, but just putting it out there.
Last edited by chobes; Jul 9, 2019 at 04:44 PM. Reason: Issue solved
Joined: Nov 2003
Posts: 11,329
Likes: 346
From: Jacksonville, FL (originally from Toronto Canada)
I presume you've tested both A/C fuses (20A in the fuse panel and 15A under the hood)? Then test that you have full system voltage on the pink wire at the A/C relay socket. Next, you could try bypassing the relay by removing it and then placing a small jumper wire in the socket between the pink wire and the dark green wire (not the dark green/white wire) and see if the compressor clutch engages. If it doesn't then you have a problem with the wiring between the relay and the clutch or with the clutch itself. If it does then you've got a problem with the PCM activating the relay or with the relay or its socket - despite having replaced the relay. The dark green/white wire should go to ground when the PCM is activating the relay.
Pulled the fuses and found the issue. Current across the 20A fuse, but none across the 15A fuse. Replaced with a new fuse, and AC kicked on immediately. Upon close inspection, there's an almost invisible crack in the fuse near one of the blades, not clearly blown. It's a bit strange, as I watched the mechanic test the fuses, but happy that it was such a simple fix.
Props to WhiteBird00 for the reminder to check/verify/rule out the simple stuff first.
Props to WhiteBird00 for the reminder to check/verify/rule out the simple stuff first.
