Weird issues with Saturn sl1

[Orangepeel]

When I bought my 2000 sl1 the previous owner had the bcm replaced with a used unit. So it had a mismatch code for the air bag system and the mileage was wrong. I thought I’d try to reprogram them using GM’s tech line tech 2 software. So i did just that. It didn’t fix my issue and now I get a power steering assist code along with the a/c not engaging the compressor and the rear defrost doesn’t work. The a/c button acts like it works button pushes in light comes on but compressor doesn’t engage. The rear defrost button feels like there isn’t anything there button doesn’t stay in doesn’t click etc. also the driver door unlock isn’t functional. Weird issues! Any help is appreciated.

 

[Orangepeel]

Here are the only codes the car has. PCM has 2 codes and the air bag module has the same code it always has

 

[eljefino]

I'd pull the BCM and check its numbers on its label; I bet it's for a wrong year.

Where did you get the firmware you hoped to reflash this with?

I've had a bunch of saturn s-series. As you know you have the gen 2.5 with motorola PCM and modest changes for 2000-2002.

We also have to backtrack and ask why the PO switched BCMs if not for a problem that he maybe didn't cure.

 

[Orangepeel]

I'd pull the BCM and check its numbers on its label; I bet it's for a wrong year.

Where did you get the firmware you hoped to reflash this with?

I've had a bunch of saturn s-series. As you know you have the gen 2.5 with motorola PCM and modest changes for 2000-2002.

We also have to backtrack and ask why the PO switched BCMs if not for a problem that he maybe didn't cure.

I believe the blower motor wasn't working so the shop he took it to recommended a bcm. Before i Messed
with it, everything worked except an airbag light for the mismatch code, and the mileage was wrong. But other than that functionally everything worked perfect for what I understand the shop that did the BCM did a used one. Which I believe would explain the incorrect mileage.

The software I used is tech line from GM. I actually paid For the GM programming software. I used a pass through cardaq by Drew technologies. I have programmed many of the newer Silverado six speed transmissions after replacement and things like that. I never used it on an older car like the Saturn simply because we just don’t see them at the shop anymore. But somewhere along the way something when awry.

 

[Orangepeel]

Well to add to the fun I decided to start diagnosing it. No power to the A/C compressor . No power at the Gray wire which is the relay control wire from the pcm. Bypass the relay and the compressor runs. So I had another pcm so I did the key turn style program to program it and tried the other pcm. Car runs and all that but same issues as before.
Also odd factoid I can actuate the lock on the driver door lock and unlock etc works fine. But the door switch won't unlock the driver door it will unlock the others though so the switch is working. Weird issues!!!!!
Maybe the programming corrupted the bcm?
I've owned the car almost a year and just decided to try to get the air bag light off by reprogramming everything etc..... Should have just left it alone I guess.

 

[Donald]

How much is a 25 year old Saturn worth? How much time & money do you want to put into it?

 

[clinebarger]

A/C REQUEST
A/C request is made by the HVAC control head supplying voltage to circuit 603 to the BCM. The BCM will then request over the serial data link to the engine controller to operate the compressor. The BCM provides evaporator freeze protection by monitoring engine speed and ambient temperature.

Monitor the A/C Request PID in the BCM data list.

 

[clinebarger]

The U1000 could be caused by the airbag misconfiguration.

 

[clinebarger]

P0637.....EVO solenoid or wiring to said solenoid.

 

[Orangepeel]

How much is a 25 year old Saturn worth? How much time & money do you want to put into it?

It's completely rust free and looks new underneath which is about unheard of, it also has only 110k on it. But to answer your question I love these little cars and plan on keeping this one indefinitely. It doesn't get driven in the rain or snow etc.

 

[Orangepeel]

A/C REQUEST
A/C request is made by the HVAC control head supplying voltage to circuit 603 to the BCM. The BCM will then request over the serial data link to the engine controller to operate the compressor. The BCM provides evaporator freeze protection by monitoring engine speed and ambient temperature.

Monitor the A/C Request PID in the BCM data list.

Did this earlier today it is not being requested on even though the button lights up

 

[clinebarger]

Jump the two wires at the high/low (binary) pressure switch together temporarily.....If you now have request, Suspect a faulty pressure switch assuming the correct amount of refrigerant is in the system & the connector doesn't have spread terminals.

 

[Orangepeel]

Jump the two wires at the high/low (binary) pressure switch together temporarily.....If you now have request, Suspect a faulty pressure switch assuming the correct amount of refrigerant is in the system & the connector doesn't have spread terminals.

Did that and nothing. It's not getting the request even when the button is actuated

 

[clinebarger]

Check for a near 12vdc signal at the pressure switch....This is a high impedance circuit that will carry little to no current. Use a DVOM or a Scope.

 

[Orangepeel]

Check for a near 12vdc signal at the pressure switch....This is a high impedance circuit that will carry little to no current. Use a DVOM or a Scope.

I checked the high pressure switch and had nothing.

 

[clinebarger]

With a Incandescent test light hooked to battery positive....Probe both circuits at the pressure switch one at as time while monitoring the A/C request PID....If one requests A/C, The wiring from the pressure switch & BCM is good.

The LED indicator & Request signal are on 2 separate resistors inside the A/C Control Head.

 

[Orangepeel]

With a Incandescent test light hooked to battery positive....Probe both circuits at the pressure switch one at as time while monitoring the A/C request PID....If one requests A/C, The wiring from the pressure switch & BCM is good.

The LED indicator & Request signal are on 2 separate resistors inside the A/C Control Head.

Neither wire gets anything test light doesn't fire on either

 

[Drifter]

Check connections and pin fittings. Maybe a loose pin or break in the wiring. PHAD Youtube ch has some great videos on these types of issues. Ivan is amazing at diagnostics. Best of luck to ya.

 

[Auto tech]

Sounds to me like clinebarger is leading the OP in the right direction

 

[clinebarger]

Unusual to have 2 separate problems on the same circuit...But not impossible on a 25 year old vehicle that's had some hands on it.

Check for good terminal "drag" at the BCM (Connector J3, Pin A10), If good back probe with a T-pin or Sewing needle & do the test light to B+ test again.

Same at the A/C control head, Pin C, Then test with a DVOM.