This is on my 98 SSE Bonneville with the Bose amplifier and automatic HVAC.

I just replaced the factory radio with a new pioneer headunit I have the wiring kit and hooked all that up and added a connector for the remote turn on so the bose amp works to power the speakers.

When I turn the car on with the new head unit the digital climate control its display just shows "--", but when I connect the factory unit it functions correctly.

My best guess is that the problem is from the Diagnostic Signal - E&C wire that now is not connected to the factory radio. (FSM Radio C2 - Pin 15 - Circuit No 835)

I'm not sure what I need to do to get it to turn on any suggestions?

Just to note I do not have a PAC unit for it yet.

Also I took some measurements of the wire in question.

Radio not connected:
5.6v Ignition off
4.4v Ignition run
4.8v Engine running

Stock radio connected:
7.25v Ignition off/run
8.6v Engine running fans on

I tried to trace the circuit in the stock HU with no success as the trace flips from one side of the PCB. I looks like the wire runs to a capacitor but it is hard to tell since there are 3 traces that go under the capacitor and i cant see under it.

does the CC function with nothing plugged into the radio connector? just trying to find out if its coming from the radio or CC or if something on the new radio is interfering with the bus signal.

If nothing is connected then the ECC does not function properly*, if I plug the stock radio back in it will have the dashes flash for a sec then start working.

* = The fans will turn on after the car gets up to temp but I cannot control it see the temp or use the defroster.


The only two wires not connected to anything now are pin 16 and 15

Pin 16 = steering wheel audio controls. (I believe that is the pin it is on or its 14 if it counts the other direction)
Pin 15 = Diagnostic Signal - Entertainment & Climate

The third pin on that side is a ground at pin 20 I added this pin and tied it into the ground even though it was not needed. (Note: function was the same when this ground was not connected.)

i cant think of why that would happen. i did a few searches and found a few who had changed the radio, most forgot to hook up the amp, no one says anything about the hvac. i have a 98 and it doesnt do anything that would think they would be connected in any way. just go over your wiring 100% make sure you didnt wire something so it jumping on to the signal. beyond that im sorry. im interested though please post the fix if you find one.

I checked the wiring and it all seems fine each speaker is correct, power, switched, ground, and remote are all hooked up. I connected an insulated spade terminal to the remote wire to hook up the power antenna and have an easy point to connect the BOSE amp and add a second amp later.

I forgot to mention that I did not connect the orange and orange/white wires since my HU does not use the illumination and dim wires. Could that be a problem? I do not think that it would be a problem as I have not used those two wires when hooking up my 01,03 GP 93 Bonneville or 93 LeSaber that had ECC.

JwFireBird could you look at your wiring harness and see if you have any thing hooked up to the two green wires that are on there own bank with a ground next to them?

if its something i have to take apart to see i wont be able to till fri. where are you talking about?

All you will need to do is slide your after market radio out enough to see the white connector for the stock radio.

its got the stock radio, my wife drives it. i always put aftermarket radios in my vehicles but she dont want me messing with hers. i can pop the radio out but it will have to wait till fri. does the trim pop off with clips or something?

The trim just pops off I usually start with the part just to the right of the steering column and slowly pull.

Since you only have the stock unit in the car can you unplug the unit and see if the ECC will work.

Thanks

as soon as i get some time when shes not using it. friday most likely