Can't wait for winter to end. Car is acting funky.
Got in today and the Ext temp words are blinking on the climate control for about 2 min when *=tarting?
What does this mean? Never did this before?

Grab the code(*) first so we can pinpoint the problem

To Enter the Diagnostic Mode:

1. Press the "EXT TEMP" button then press the "ECON" button. Hold both buttons for three seconds. -00 will be displayed, indicating entry to the diagnostic mode.
2. -00 is also called a diagnostic pointer. A diagnostic pointer indicates the parameter which can be displayed. To move through the list, press "FAN" button. To display the information in a diagnostic pointer, press the "EXT TEMP" button.
3. Diagnostic pointers -40-41 and -42 are output commands which allow you to control the position of the Air Mix Valve, the program number or the air delivery mode. To enter an output command, press the "EXT TEMP" button when the desired pointer number is displayed, then use the "TEMP" button to change the commanded value.
4. To exit the diagnostic mode, press the "OFF" button. To exit from a diagnostic pointer, but not from the diagnostic mode, press the "FAN" button. Note: A two-digit trouble code indicates the fault is present now. A three-digit trouble code indicates the fault was present. Clearing Codes

o Clear codes from the Heater And A/C Control Assembly by removing Fuse 11.

To summarize, press & hold ECON and EXT TEMP for 3 seconds until -00 is displayed. Then press EXT TEMP to view codes. Press OFF to leave diagnostic mode.
00 = No system faults
01 or 101 = In-car temp sensor short
02 or 102 = In-car temp sensor open
03 or 103 = Ambient temp sensor short
04 or 104 = Ambient temp sensor open
05 or 105 = Air mix valve feedback circuit open

This procedure is also in Techinfo. Please note to the other readers......this doesn't work on ECC'* after the 93 model year.

The procedures in Techinfo are for the 93 (and perhaps 92). The above diagnostics are for a 90 specifically. It needs be verified by someone with a FSM if it is the same for 88-89 & 91.

Looks about right. [checked '89 FSM].


-justin

took climate control off 90 deg. and light stopped blinking.thanks for the info if it does it again.

we need to get something for 94 and up

FWIW, I was having the same 2min flashing pblm on my 93. The cause was from my self-change over of the AC system to R134a.

What I was having to do is wait for the display to stop blinking, run the temp down to 60, wait about 1 minute and then run the temp up to 70. This would cause the damper door to properly adjust to a heat position.

However, the other day I got lucky. I had yet to try the diag steps listed above, but found that taking the temp down to 60, waiting 2 minutes and then shutting down the car, the system reset itself. Please note, I stumbled across this, but it did work

The instructions for your car are located in the techinfo section. Here is the link http://www.bonnevilleclub.com/techinfo/?article=45

The above instructions are for a 90 and a little different.