Trouble Codes, Accessed in the Climate Control, other neat info

[ffmeltdown]

well 126 came back but i have no issues that i can tell. i'll try hooking up my scan tool just to see if anything shows up. I agree Trans temp would be nice to know but it may be more of a switch than a sensor, i dunno.

 

[MrBuick (Magnum)]

I don't think there is a trans temp stock. There is no temp sensor for the trans, as far as I know. There is a sensor on the pass side of the trans, on the cooler line, but I'm pretty sure that is for line pressure, so the PCM knows if it gets too high, or if it drops off. There is a line pressure test port, on the drivers side of the trans. It looks like a threaded outlet, with a threaded plug in it. That is the easiest place to put a trans temp sensor in. I have one on my RMS.

 

[reure]

I was curious about the trans temp being sent to the PCM. I found it in the wiring diagrams

-24 could be the Trans temp.

 

[cadet57]

Just tried it, it works in my '92 RMW.

 

[MrBuick (Magnum)]

I will have to compare -24 to the trans temp gauge in my Roadmaster. When I first learned the outputs, I thought that's what that one was.

 

[jae w]

Can u clear the codes like u can on a caddy?

 

[saltfevr]

I believe if you have a OBD1, 1994-1995, you simply disconnect the negative battery cable a few mins. If its 1996(OBD2) EPA wants the computer to store the trouble codes, and can only be erased thru a special scan tool. Hope this helps.

 

[turbostar]

I know there are not a lot of engine swappers on this board as most enjoy the roadmasters as they come from the factory,but to an engine swapper like myself this thread is good news. One of my cars is a Fiero with a Northstar transplant and the Northstar dash is also a diagnostic center. I pulled the Northstar dash out of the donor car and have a pigtail I built that allows me to hook it up to the Fiero for troubleshootong. I think(from memory) that it takes 6 wires. Since I'm swapping the drivetrain from one of my two 95 roadmasters into my 65 pickup,I will also remove the necessary dash part from the donor car and use like I do with the Northstar. When I get around to identifying the wires for the pigtail,I will post incase anyone else wants to do it.

 

[Albert96]

i know this thred is old but I am curious to know what code 126 is? It is on in my car as well. thanks for the help
* correction ---- I have 2 codes to question about, under the HVAC (2) code 126 and 110 are there.
Albert

 

[heath_94RM]

I believe it is "A/C high pressure switch disabled A/C compressor" I have seen this code also. I am guessing that the A/C needs recharging.

 

[Albert96]

My a/c is ice cold, is that the 126 or the 110 code?
Thanks

 

[heath_94RM]

126 is what I'm seeing. Did an internet search for GM codes and thats all I could find.

 

[heath_94RM]

I think I finally figured this out. A 1 in front of the code means it happened in the past (see below). 26 is Serial Data Communication error (shorted/open). I wonder if perhaps a 26 would be set if the battery was disconnected and then reconnected? My Electronic HVAC control seems to work fine, but I have had the battery disconnected a number of times doing various work.

10 is Air mix motor circuit (open) and 11 is Air mix motor circuit (shorted). Perhaps a problem with the air mix motor or wiring?

To enter diagnotic mode:

With the ignition in the "RUN" position (engine does not necessarily need to be running, but it will work either way).
Push (and hold) "OFF" and "WARMER" simultaneously on the Electronic Climate Control (ECC) until all telltales lights illuminate (segment check).
Release the "OFF" and "WARMER" buttons.
System is now in diagnostic mode. "00" (zero-zero) should now be displayed. This is the pointer.
Pressing "OUTSIDE TEMP" will allow you to display the corresponding code for the pointer.
Use the "FAN SPEED" override switch (UP/DOWN) to increment or decrement the pointer number.
Pressing "AUTO" or turning the ignition switch "OFF" exits diagnotic mode.
Pointers 00-04 contain the stored trouble codes.

"00" = Powertrain Control Module (PCM) codes
"01" = Central Control Module (CCM) codes
"02" = Heating, Ventilation and Air-Conditioning (HVAC) codes
"03" = Supplemental Inflatable Restraint (SIR) codes
"04" = Anti-lock Brake/Traction Control System (ABS/TC) Codes

Codes prefixed by a "1" are history codes.

A code can be cleared by pressing the "OFF" button while that particular code is being displayed.
🙂

 

[Albert96]

Ok cool, how do you reset or clear the code? So I can see if it comes back.

 

[heath_94RM]

A code can be cleared by pressing the "OFF" button while that particular code is being displayed.

 

[gallojr]

Re: Trouble Codes, Accessed in the Climate Control,

Love it ... great to have a Tach. I'm trying to get my fan to turn on, without turning on the AC. thanks for the cool hack. But I don't get a reading on the first four -00 test??? any thoughts
thx
new....
95 Buick Roadmaster

 

[ARCStig]

This is very useful. Cleared my error code, whatever it was...dose anybody know what "09" means when entering diagnostic mode? I have a '93 so this works a little bit differently, but atleast my error code has been cleared...somehow...I just left it on 09 for a few seconds and when I exited diagnostic mode, the Fahrenheit indicator stopped blinking. 🙂

 

[rivbandit]

So I was looking for help with my 95 Roadmaster. 66k original miles not being driven regularly. "summer storage, outside. Day1 of issue: Everything fine till one day she wouldn't start unless I pressed the gas to the mat. Even then had to feather the throttle to keep her going. Day 2: After tinkering i.e. making sure the fuel pump was pumping etc., I got her to run but not great. idles Ok now but touchy on light acceleration even in park. Overheats with no fans coming on. Never ran hotter that 1/4 before... Starts now without matting the pedal but still hesitates on initial acceleration. And gets hot just idling, no fans still.
ANY THOUGHTS???

 

[buickwagon]

Neither -24 nor -08 are the coolant temperature on my car -- a 95 RMW with the mechanical fan HD cooling package.

With the car stone cold from sitting overnight, ambient air temperature was 19.1°C. My scan tool (OTC 4000E with Pathfinder 97 software) showed a coolant temperature of 20°C, a transmission temperature of 20°C and the torque converter temperature switch "Off". KOEO, I put the CC into the diagnostic mode. By the time I selected -24, it was displaying a value of perhaps 40 or 50, but climbing! It eventually climbed to 175 and stopped -- without ever starting the engine. Similarly, -08 started low and climbed to 91.

Leaving the key on, I unplugged the coolant sensor at the waterpump. The scan tool value immediately dropped to -40°C. -08 and -24 remained at 91 and 175, respectively. Plugging the coolant temp sensor back in restored the scan tool value to 20°C, leaving the others unchanged.

I unplugged it again and went through all the possible settings, from -00 to -38. Nothing changed significantly.

Turning the key off for a few moments allows both to drop, but both then start climbing again as soon as the key is turned back on. Exact values are difficult to determine since it takes time to put the CC back into diagnostic mode each time the key is cycled.

Given the way these act, I suspect the value is related to something that takes time to charge or heat up -- perhaps an airbag sensor or heated O2 sensor (although, I don't think the O2 heater current is monitored, so I don't see how it could be that. Maybe a simple timer?)

It might be useful if a few people checked a variety of years/models/option packages with a cold engine to see if my results are typical.

 

[bluebell95]

Hi I know this is a reply to an old thread, possibly sticky, but is there a more complete list of the -XX descriptions? Having -00, -01, -02, -03, -04 is great, but I went through all my options on my 95 RMS and have no clue what many of the others are. I read somewhere that the 1xx are historic, but in my example below, what is option -13 with value of 28? Am I making sense?

05 70
07 56
08 102
13 28
16 115
17 128
18 117
19 129
20 155
21 155
22 180
23 60
24 36
25 154
26 190
27 02
28 124
29 24
30 86
31 86
34 128
35 128
36 13
37 61
38 05