I'll bet this is a one-off...

[ACDiecast]

Okay, so here's the background.

I had been driving my LS to work (about 12 miles) without issue on and off all summer. A few weeks ago, I parked it from work on Friday night and spent the next few days on vacation. When I returned to drive it to work the following Wednesday morning, it was cool enough that with the Auto climate setting I didn't notice the A/C wasn't working. Finally, when I left work that afternoon it was apparent. After I lifted and inspected the pressures and temps in the lines, I took off the cowling underneath to find enough dye in the back of the compressor to see with the naked eye.

That's what led me down the Cooling fan path. I figured the high pressure blow-off valve worked as it should to vent the R-134a when the pressures got too high. Using my MaxiSys, I attempted to turn the fan on manually but it would not. I could still use the scan tool to cycle other actuators, so I figured it wasn't the tool's fault.

Long story short, after purchasing a new Dorman part and tearing the engine bay apart to get to it, the Dorman one had the same symptoms. I still can't get it to turn on with the MaxiSys under direct control, but when the doing a systems self-test, it will turn on the fan at a pretty slow speed momentarily. This is making me believe that the PCM isn't sending the correct (or any) PWM signal when it needs to.

Anyone had anything similar happen?

I would really appreciate any ideas at this point, before I try and take it to a dealership.

 

[joegr]

I expect that you may be a little off base here...
I think you have a 2nd gen (wish people would post that). In the case of the 2nd gen, the fan test is very brief. Note that the fan won't come on if there is no/low AC pressure and the engine is not hot.

The AC system will not vent because the fan isn't working. There is a high side pressure sensor that would turn the AC off before it got high enough to trigger the pressure relief. The pressure relief valve is usually only triggered if the condenser is clogged internally. I suspect that the o-ring at the scroll control valve at the back of the compressor is leaking. It leaks the compressor oil out first, so if the refrigerant is gone too, then the whole thing may be messed up now, but hopefully not.

Note that the PCM has to send a very particular off command to the fan continuously to keep the fan off. The fan will failsafe to maximum speed if it gets no control signal from the PCM. If you have an 03 or 04, then you have the fan with two connectors. The smaller connector is the control signal and electronics power. Disconnect it, and jumper the Green/yellow wire across the two connectors. With the key on, the fan will run at max speed.

 

[TooManyToys]

With my '03 as soon as you disconnect the small connector the fan goes into high speed.

 

[ACDiecast]

Thank you folks, I'm going to try this as soon as I get back in town. I'm sorry I forgot to mention my 2003 is a 2nd Gen.

If that's correct, why would the high pressure relief valve blow off the high side freon in the first place? Ambient temps were in the low 80's, if I remember right.

 

[joegr]

...If that's correct, why would the high pressure relief valve blow off the high side freon in the first place? Ambient temps were in the low 80's, if I remember right.

You haven't convinced me that the pressure relief valve did open. I still think you have the common leak from the scroll control valve o-ring.
BTW, it's not Freon (R-12), it's Suva (R-134a) - or generically, refrigerant.

 

[ACDiecast]

First off, thank you for the valuable replies. I have finally had time to look deeper into this.

I tried both the suggested tests to check the fan's operation, unplugging the smaller connector while KOER or KOEO didn't start the fan. However, jumping the green/yellow wire while KOEO made the fan default to high, as Joe suggested. The problem still remains that I cannot get the cooling fan to turn on.

I tried this next test twice. With PIDs for coolant temp, engine RPM, ambient air temp, and a few others monitored, I started the engine and set a throttle stick for about 1500 RPM, a little above high idle. Allowing the coolant temps to get above 215, I listened for the fan to start, and turned the A/C on (although the compressor clutch didn't engage, assuming this is because I still haven't replaced the R-134a that had leaked from the system, giving low refrigerant pressures). The coolant temps got to just around 221 before I shut the engine down, noting that the coolant temp gauge on the dash was still right around midpoint, maybe only a small tick higher than "normal."

This is when I noticed that the MIL was on with a confirmed P0113 DTC for Intake Air Temperature Sensor 1 Circuit. Freeze frame showed the coolant temp at 98.6, the RPM at around 1400, and the intake air temps at -40F. However, I believe this is attributed to the fact that I had pulled the vehicle in and out of the garage with the air ducting off and the MAF sensor disconnected. I cleared the code and attempted the test again. The results for the second test were identical, trying the A/C once again at around 215 and running until around 221.

Mitchell shows the green/yellow wire going through fuse 5 under the hood, and having 12v at the connector on the fan housing. I verified having a full 12v at both the fuse panel and connector. After finding where the white/black wire on the smaller connector goes into the PCM, I am going to do a continuity and resistance test on the white and black wire between the PCM and the connector. I'm not quite sure where else I can go at this point.

Am I wrong in assuming this may be a PCM issue?

 

[joegr]

I'm not sure that the PCM would turn the fan on at 215, but I would have expected at least a low speed by 220. It should be high by 230. Note that the gauge will not move at all past the mid point before 230, or maybe a little higher. Turning the AC on with low/no pressure would not be expected to do anything for the fan. The PCM (fan wise) responds to high side AC pressure, not the act of turning the AC on.

 

[ACDiecast]

Update: The fan does run at what I would consider to be a quite low speed at 220, and the highest I could get it was 224 momentarily, 222 consistently, with a high idle of 1700 RPM.

 

[ACDiecast]

You haven't convinced me that the pressure relief valve did open. I still think you have the common leak from the scroll control valve o-ring.
BTW, it's not Freon (R-12), it's Suva (R-134a) - or generically, refrigerant.

-UPDATE-

As of a few days after the refrigerant lines were vacuumed and the Suva recharged, the A/C once again stopped working after the refrigerant leaked out for the second time. Dye is visible on the bottom side of the compressor, likely near the scroll control valve o-ring. Is this item serviceable?

 

[joegr]

-UPDATE-

As of a few days after the refrigerant lines were vacuumed and the Suva recharged, the A/C once again stopped working after the refrigerant leaked out for the second time. Dye is visible on the bottom side of the compressor, likely near the scroll control valve o-ring. Is this item serviceable?

As I said, that seems to be the common leak.
It's easy to change.
Scroll Compressor Control Valve O-Ring / Gasket MS-235G G12-3101 Ford / Saturn | eBay
Note that you will have to replace the lost compressor oil, PAG-46. Also lubricate the new seal with the PAG oil before installing it.