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I've been working on this one with my dad for a few weeks and looking for some direction, advice or personal experience!
The A/C in the car works intermittently, and seems to be getting worse over time, but that could be my imagination. At this point the A/C rarely works.
The problem as far as I can tell is that the Clutch is not being commanded to engage the compressor. When the A/C is working everything appears normal and the air blows perfectly cold.
We started with the Auto Active test and that passed, so my understanding is that the IPDM is not the problem. We checked the pressure on the high and low side when the clutch decided to work and the readings appeared normal. Based on the pressure readings we got and the A/C blowing cold when it is working, I don't believe that the problem is a leak or low refrigerant. We also tested the refrigerant pressure sensor and that gave us 1.4 V when the system was not operating and 2.4 V when it was working, the service manual I have says anything between 1-4 V is in range, so I think the refrigerant pressure sensor is OK. I don't think the problem is the Clutch or the Compressor either because when the clutch is not engaging we are not getting power from the IPDM to command the clutch to engage, leading me to believe that the problem exist upstream from the IPDM or within the IPDM if the auto active test doesn't 100% rule it out. We checked some of the wiring between the Front Air Control and the Body Control Module following the flow chart in MTC-39 found here https://cardiagn.com/manual-air-conditioner-versa-2012-h/ and thought that maybe there was an issue with the BCM and swapped it out, but we're experiencing the same issue with a different used BCM. We depinned wire 10 out of the IPDM which is where the IPDM sends power to the clutch and gave it power to see if the wiring from the IPDM to the clutch is good and we got the clutch to engage on that test. For some reason the IPDM is not sending power to the clutch even though we are commanding A/C at the Front Air Control. Things get a little tricky to test between the BCM and the IPDM because they are connected via Can line communication and we don't have the tools to see what kind of data is flowing over that line. When we hooked up a 2 way OBD2 connection the ECM would show an intermittent command for the A/C as well. The A/C signal is getting lost somewhere in the computers (IPDM,BCM,ECM) or before that.
My dad's big question is that when looking at BCS-13 https://cardiagn.com/body-control-system-versa-2012-h/ , the manual shows a test for the "compressor on signal" and when we hook up the probes instead of 0 V and 5 V for an A/C Switch On and Off respectively we are getting 0 V and System Voltage, some 13 V give or take. Any thoughts on why that would be?
Our big question is what would cause the IPDM to intermittently send power to the clutch when it passes the auto active test? any good ways to test the can lines? is it possible that there could be a problem with the signal from the Front Air Control?
The A/C in the car works intermittently, and seems to be getting worse over time, but that could be my imagination. At this point the A/C rarely works.
The problem as far as I can tell is that the Clutch is not being commanded to engage the compressor. When the A/C is working everything appears normal and the air blows perfectly cold.
We started with the Auto Active test and that passed, so my understanding is that the IPDM is not the problem. We checked the pressure on the high and low side when the clutch decided to work and the readings appeared normal. Based on the pressure readings we got and the A/C blowing cold when it is working, I don't believe that the problem is a leak or low refrigerant. We also tested the refrigerant pressure sensor and that gave us 1.4 V when the system was not operating and 2.4 V when it was working, the service manual I have says anything between 1-4 V is in range, so I think the refrigerant pressure sensor is OK. I don't think the problem is the Clutch or the Compressor either because when the clutch is not engaging we are not getting power from the IPDM to command the clutch to engage, leading me to believe that the problem exist upstream from the IPDM or within the IPDM if the auto active test doesn't 100% rule it out. We checked some of the wiring between the Front Air Control and the Body Control Module following the flow chart in MTC-39 found here https://cardiagn.com/manual-air-conditioner-versa-2012-h/ and thought that maybe there was an issue with the BCM and swapped it out, but we're experiencing the same issue with a different used BCM. We depinned wire 10 out of the IPDM which is where the IPDM sends power to the clutch and gave it power to see if the wiring from the IPDM to the clutch is good and we got the clutch to engage on that test. For some reason the IPDM is not sending power to the clutch even though we are commanding A/C at the Front Air Control. Things get a little tricky to test between the BCM and the IPDM because they are connected via Can line communication and we don't have the tools to see what kind of data is flowing over that line. When we hooked up a 2 way OBD2 connection the ECM would show an intermittent command for the A/C as well. The A/C signal is getting lost somewhere in the computers (IPDM,BCM,ECM) or before that.
My dad's big question is that when looking at BCS-13 https://cardiagn.com/body-control-system-versa-2012-h/ , the manual shows a test for the "compressor on signal" and when we hook up the probes instead of 0 V and 5 V for an A/C Switch On and Off respectively we are getting 0 V and System Voltage, some 13 V give or take. Any thoughts on why that would be?
Our big question is what would cause the IPDM to intermittently send power to the clutch when it passes the auto active test? any good ways to test the can lines? is it possible that there could be a problem with the signal from the Front Air Control?
