A/C pressure sensor switch for the low pressure side location

Good evening,

I attached a picture of the location and the procedure.

Why do you believe that it has failed?

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak

I attached a wiring diagram for you of the A/C system. Do you have a test light to do some checks?

https://www.2carpros.com/articles/how-to-check-wiring

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Roy

Removal

NOTE: Removal steps in this procedure may contain installation details.

1. WARNING: Before beginning any service procedure, refer to Safety Warnings in General Information. Failure to follow this instruction may result in serious personal injury. See: Vehicle > Initial Inspection and Diagnostic Overview

Refer to: Climate Control System Health and Safety Precautions See: Vehicle > Technician Safety Information > Climate Control System Health and Safety Precautions (General Information). See: Vehicle > Initial Inspection and Diagnostic Overview

2. Torque: 7 Nm


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Help See: Vehicle > Components > About This Information

Installation

1. To install, reverse the removal procedure.

That's the video I'm going off of, actually. I've tested the pressure and it's good and should be engaging the clutch. However, that's not happening. I'm grabbing the gear to do a OBD2 system check and the test light tomorrow. After the KOEO test, I'll start working on the sensors to see what it might be. Fuse is good and relay seems fine. Swapped it out with same results.

Okay, what is the pressure? What is the numbers on the high and low side?

I attached the wiring diagram for you.

You will need a voltmeter to check some voltages at the pressure sensor.

https://www.2carpros.com/articles/how-to-use-a-voltmeter

Let me know when you are ready to do some testing

https://www.2carpros.com/articles/how-to-check-wiring

Roy

The low side pressure is 100. The high won't read because the A/C won't cycle.

The high side should read no matter what. Do you have a gauge set? It needs to be hooked to both the high and low side.

Roy

I have a gauge set and it read as indicated. I'll hook it up again tomorrow/this week to verify. However, I have zero reason to believe that the refrigerant is the issue. It worked fantastic one day and the next, it did not. Short of a line completely blowing off, I cannot see it leaking all out from one day to the next.

That being said, I got the OBD2 hooked up and it read the p0532 error. So, how likely is it the sensor is bad (which one?) vs another electrical problem throwing the code? Is there an easy way to troubleshoot that specific sensor? Thanks, again, for all the help!

You never gave me a high side reading. I need that reading and the low side while the A/C is on.

Below is the description of the code and attached is the flow chart for determining the failure.

Roy

Climate Control System - Vehicles With: Dual Automatic Temperature Control (DATC)

Pinpoint Test(s)

P0532, P0533


Normal operation and Fault Conditions

The A/C (air conditioning) pressure transducer receives a ground from the PCM (power-train control module). A 5-volt reference voltage is supplied to the A/C (air conditioning) pressure transducer from the PCM (power-train control module). The A/C (air conditioning) pressure transducer then sends a voltage to the PCM (power-train control module) to indicate the A/C (air conditioning) pressure.

DTC Fault Trigger Conditions


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Possible Sources

Wiring, terminals or connectors

A/C (air conditioning) pressure transducer

PCM (power-train control module)

Visual Inspection and Diagnostic Pre-checks

Inspect for loose or corroded PCM (power-train control module) and A/C (air conditioning) pressure transducer connections.

Both sides read around 100 when connected with the vehicle off and cold. Upon heating, they both go up to a bit over 100. This is without the clutch engaging, of course. Ran some KOEO tests and the clutch did not engage, but fans came on. Relay test shows power being supplied through the relay. I'll hit the pinpoint tests some time this week. Just let me know where I can start and I can start the first chance I get.
Cleared the codes and the previously mentioned code is no longer coming up. During the KOEO tests, no faults are found.

Okay, go to the clutch relay. Remove the relay and with the key on, test for power at the terminals.

You should have 2 powers with the key on.

The diagram I posted back in the beginning.

Roy

Yes. Two powers with key on for relay. Relay clicks on insert, as well. No power to fuse without relay. Power to fuse (both sides) with relay in.

If the relay energizes when you put it in, check for power to the compressor connector.

If it has power, the compressor is the issue.

https://www.2carpros.com/articles/replace-air-conditioner-compressor

If it does not then good chance the relay is the issue.



Roy

There does not appear to be power at the compressor connector. However, the relay was the very first thing I replaced. When it didn't work, I put the old one back. I'll give the new one another shot and check for power at the compressor?

Same result. No power at compressor connector.

Okay, then it sounds like you have an open wire between the relay and the compressor.

Roy

Great! What's the best way to trace the wire to the relay, or the most likely place for a fault? Thanks!

I do not have a routing diagram of the wire. I would start at the compressor and work your way back. Look for any areas where it gets hot or the harness is damaged.

Roy

Will do. And, I'm tracing the violet/wht wire from the look of the diagram, correct?

That would be correct. That goes from pin 87 of the relay directly to the compressor.

Roy

There appears to be a plug with 3 wires underneath the intake manifold where the wires have been pulled from the plug. The wire colors appear to be yellow/brown, green/brown, violet/green? Is this completely unrelated? It seems too coincidental to be unrelated.

Can you upload a picture of what you see so I can see it?

Roy

More likely a plug with yellow/violet, green/violet, and violet/green? It appeared to be plugged into the harness coming from the alternator.

Did you respond? I got an email but nothing came through.

Roy

As you can imagine, it's quite difficult to get a picture of the place the plug goes. In the second picture, you can see the plug receptacle in the background and in the final picture, you can see the three wires that go to it in the foreground. As I stated in the previous post, it appears to go into the harness for the alternator? I'm adding a 4th picture of the plug going towards the alternator.

That got ripped out or cut out.

Can you find the 3 wires that go to that connector?

Roy

Here's the picture of it going into the alternator. Yes, I can reach the three wires that go into the plug, although it's somewhat difficult. Is this likely the issue, or a completely different issue?

Okay, you are going to have to remove the wrap from the harness and the tape around the harness to expose the wires and you can do the repair.

You will need to solder and shrink wrap the wires back together.

Since the color wire for the compressor is there, I would say yes to being the issue.

Roy

There's not quite enough wire on the connector. Can I remove the wires from the connector, or a new one? Suggestions?

Yes, you would need a terminal removal tool. You can get one at a part store or you could get the connector. It is called a pigtail and it comes with wires installed and about a foot in length.

A parts store should have them.Take it with you to match up.


Roy

Unfortunately, replacing the connector did not work for the A/C problem.

Did you trace the wire from the compressor to the relay?

Roy