OK, my '97 has been a solid car, never a problem. Now I'm in the middle of two issues that have me pulling my hair out.
First, let me say that since the last smog 2 years ago, I had a body shop shoot the front bumper cover, can't even remember what was wrong with it but they removed it, painted it and put it back on. Great job.
Now, I have no A/C (never checked it after I got the car back, winter, not driving it much etc), I just hooked up a gauge and 134a to the low pressure intake, it was reading 0 on the gauge, I put in enough to bring it up to about 16psi. No change. I've been through all the checks, no voltage to the compressor, no blown fuses, have not bench checked the relay in the engine compartment- maybe I should. Really frustrating. Could there have been an issue with the paint shop? Maybe something they did disconnected something, the sensor for temp is in there as is the condenser and fan, correct?? Not sure what to check next.

Then, they might have disconnected the battery. I have run 4 drive cycles according to the BMW drive plan and the one that's used here (2 min idle, 2 drive cycles, idle 5 mins..... etc.) All 5 readiness codes refuse to clear. No other codes whatsoever. SAI works fine (replaced the valve, blew air through the ports, all work fine). Do I keep driving the cycles until they finally reset??

Really frustrating. I'm sure there can be no relationship with the A/C and the
readiness codes, right? That's a stretch I know, just trying to think of all the
possibilities. I feel like the wall I'm beating my head against is about to give in!

Thanks for any ideas that might head me in the right direction.

Bruce

 

can't comment on the a/c issues, but the ready codes are a common PITA on these cars. The cycles need to be gone through twice (from cold start) before you'll have even a shot that they reset. I usually find a good long freeway drive or better yet a track w/e of WOT usually sets all my codes to "ready".

 

Chris, PITA does not cover it. I've done 4 cycles from cold start with no
results, will keep trying. Did one drive of 100 miles but was not able to
be anywhere near WOT (too many CHP, don't need for this mess to
cost me anymore than it already has...). I guess I'll keep trying the driving
cycles.

Had a bit of a breakthrough on the A/C. I checked the 3 level pressure switch
and found it was open in one position, thus turning off the compressor.
Probably due to low levels of freon. I jumped the two positions on the connector and suddenly the clutch engaged on the compressor. I'm pretty confident that my problem is just low levels of 134a. I tried adding earlier but without the clutch activating the compressor, I was not really getting anything added, or so it seems. May try adding with the clutch hot-wired and see if my pressure readings are different. I have to assume that without any compressor activity, the high and low sides were equalized... makes sense I think.
Going to think about it a bit more before adding any more 134a but at least
I've learned something...

 

OK, thought I'd post this in case it might help others with A/C problems. There's been a lot posted here, this might add a bit. I want to thank Brian Smith, Tore and many others who have posted great info here. Also, thanks to Jim Sims in Los Alamos, a great resource and tremendous help. He recommends that anyone re-charging a system with refrigerant use safety glasses, good advice.

My A/C issue seemed to me like a low Freon level problem, the compressor
clutch would not engage. I had a slow loss of cold air from the system, I didn't want to just add Freon, with the compressor not functioning, it's about impossible to add Freon or get an accurate reading of the pressures.
So, I went to the 3 level switch. It's a good place to start when you've ruled out the obvious, fuses etc...It's under the windshield cowl and easily accessed by removing the weather protection cover. Here's the switch


The plug can be removed, continuity should be checked between the top and bottom plug positions (there are 4). If the circuit is open, the switch is sending power to the compressor clutch because the switch senses the level of Freon in the system is adequate. In my case, it was not open, prompting me to think that the system was indeed low. Here's the plug removed from the
switch.


To trick the compressor clutch to operate, you must bridge the top and bottom plug connectors, I used a wire, there are other ways to do this.
Here's the bridged switch.


This should get the compressor clutch operating and allow you to add the
necessary refrigerant. Here a set of gauges really comes in handy to insure that you don't replace too much lost R134a. You just need to be aware of the ambient temps and follow the charts which are available showing correct low and high pressures. When the correct pressures are reached, remove the
jumper wire and reconnect the switch. You should now be able to turn on the A/C and have proper function. I didn't have a chance to measure temps at the vent but will do that next.

My only other concern was operation of the fan in the front left fender that cools the condenser. I did not hear it come on when I switched the A/C on
and was not sure if it was operated by a temperature sensor. So, to be
sure it was getting a signal, I checked it by locating the relay for the
motor. It's identical to the relay for the oil cooler fan and located on the front portion of the fuse panel. This photo show the receptacle for the relay, I pulled
the relay to show the areas to check.


To check it's operation, with the A/C on, measure signal to pins 2 (30c) and 3 (30) at the relay (R14). These are easy to locate, here's what they look like



As soon as I plugged the relay back in after these checks, the fan came on.
I'm not sure why, perhaps someone can help here. Either there is a temperature sensor for the fan operation or my relay was not firmly seated in the fuse block. I assume there must be a delay in the operation of that fan due
to temperatures but I can't say for sure. I will be monitoring that as the next couple of days go by.

I hope this helps someone diagnose their A/C problems. There are much better instructions posted elsewhere here, this is just my experience today with my A/C system. Thanks again to all who helped me figure this out.

Bruce

 

I don't understand why any of you cali guys bother with the rediness codes. Biggest waste of time and money imaginable.

Forget about the smog station. Go on the internet and get the number for California Smog Referee Station. If your car isn't passing smog because of OBDII, they will clear you. It costs about $8 and all you need to do is make an appointment.

 

I'm about to consider the referee, I'm going to check on Monday to see where the closest one is. I going to do two more cycles then throw in the towel. I'm not
interested in having the dealer take 300 bucks of my money just to reset some
readiness codes.

One more note on the A/C repair, I also found a bad ballast resistor in the fan
for the condenser, just runs on one speed now. I'll replace that and the one
for the oil cooler as I suspect the same situation there.....

 

A friend of mine has the OBDII issue and was told that Calif. law has changed and you can only go to the referee once before you have to fix the problem.

 

Bruce,

Great write up. My A/C stopped working this weekend, so your write up is perfect timing.

 

Glad the A/C info was helpful, post if you run into problems. There are a lot of really good A/C people here, they can get you through just about anything.

Gary, I heard the same thing. All this one referee visit will do is buy me
2 years to get the readiness codes reset. I sure hope I can do it in that period of time...

 

Is it possible that your check engine light is either missing or burned out? If so, the drive cycle will not clear the readiness codes.

 

Bruce,

Great write up an pictures too. As far as the Readiness codes you'll have to run them a few times. Luckily after my battery was unplugged not by me of course. I would run the BMW procedure a few times and I haven't had any issues with smog check or smog testing which I had to do this last time. The car passed with Flying colors.

 

Not exactly..

Unless your car is on the list, they will no longer give you a "J" exemption at referee station. 993 is not on the list. Effectively means, we have to now do the flag check, get all codes in ready mode, then smog..

There is no more bypass.