Ahhh, thank you!! Very clear now. Now all we have to do is figure a way to diagnose the problems you are having.

BTW, have you talked to a dealer to find out how much to scan your car with a Tech2 and get the detailed report?

ABOUT $100.00

OK, I am assunming you still do not have full control of heat vs. cold. I will look again in the manual to see about the loss of serial data and keep alive memory to see what more I can provide.

Ouch! Now that'* just wrong...

I'm having a similar problem with a 2000 Jimmy. I found a reset procedure for that vehicle. I don't know if it will work with the Bonneville or not, but it'* worth a try.

Re-Calibrating Actuators After Power Loss

Calibration of the Electronic Climate Control (ECC) module occurs whenever battery power is removed and then restored to the ECC module. During this calibration process the ECC module will automatically tell the temperature door to go to the full HEAT position and then to full COLD position. The ECC module records both the minimum and maximum door positions and uses this data, which is in counts, to determine temperature door settings based on customer selected temperature settings.

IMPORTANT: Do not select or use the scan tool HVAC menu during the ECC module calibration period or the ECC module will not calibrate properly.

If the ECC module has been interrupted by scan tool operation the temperature door will become inoperative. If this should occur then:

1. Turn the ignition switch to the OFF position.
2. Disconnect the scan tool from the Data Link Connector (DLC) .
3. Remove the RDO BATT fuse for 10 seconds and then reinstall the fuse.
4. Place the ignition switch in the RUN position and wait 40 seconds for the ECC module to initialize.

That is REALLY GOOD stuff Archon! It would be great if we found out that it worked for ours. It might also explain a lot of the problems 97-SSE is experiencing.

Agreed....if that works, there will be some mighty happy Bonne owners. This type of info is exactly what I was looking for in the H-body manuals, but never found anything that said anything about needing to recalibrate or reset after loss of power. There is the recalibration procedure in the manual that was posted in the other thread, but strangely no direct indication of when to calibrate.

I hope that it works. I used it on the Jimmy, but unfortunately in my case, it looks as if the actuator is bad...it never budged during the calibration process. I guess I'll be tearing part of the dash apart.

i tried the re-calibrating actuators after power loss procedure.
i see no movement of the actuator rod during this procedure.
i tried it 5 times

then i observed the rod while changing temperatures from high to low.
there is movement. about 3/4" of travel

is this the normal amount of travel?

have any members used rockauto.com for parts. there pricing is about 1/2 the dealer price for the actuator.

I spent some time this weekend trying to find something in the FSMs that could help, but there is little in the manual that helps with self diagnosis. The obvious intent is that ECC diagnosis be done at the dealer with a Tech2 Scantool. The manual says, 'The only way to display diagnostic trouble codes (DTCs) is by using a scan tool. There are no provisions for "ON-BOARD" diagnostics.' But we knew that.

As such, the manual doesn't say anything about the actuator travel either, since it assumes you are using the scan tool to diagnose. There is, however, a "Temperature Valve Link Adjustment" procedure that could be used to ensure that you had full adjustment.

Here'* a summary:
Temperature Valve Link Adjustment
1. Pull valve link from retainer on programmer output crank.
2. Start vehicle; set temperature to 32 deg C (90 F).
3. Allow 45 seconds minimum for programmer motor to move output crank to its full hot position. Then move temperature valve to full hot position; snap valve link back into retainer on output crank.

There are also a couple items I thought I'd mention here, since I didn't see them posted yet. They are basic, but...

- All these tests assume a warm engine with temps outside vehicle at 6 C (43 F).
- If vehicle was recently running, a purge delay of approx. 20 seconds may be encountered before a selected mode is activated. This delay is normal and is designed to prevent windshiled fogging.
- To prevent windshield frosting during cold start up and cool outside temps, the system delays operation modes until the engine is warm (except when defrost is selected).

As far as rockauto.com goes, I know I've seen that some people have used them. We've also used gmpartsdirect.com and a couple others that currently escape my memory.