Mailbag: No A/C, Here are the Codes

[Bruce Nunnally]

Brad writes:

code IPM bo429 and IPM b1004 are the codes i am getting.

the trouble is ac blowing hot air.added freon already.

bo429 is temp control #3. b1004 keep alive memory.

what do these mean.how do i fix?

[bkc928]

tes:

code IPM bo429 and IPM b1004 are the codes i am getting.

the trouble is ac blowing hot air.added freon already.

bo429 is temp control #3. b1004 keep alive memory.

what do these mean.how do i fix?

[Cadillac Jim]

The B0429 is for the rear seat temperature control door. If you had a low Freon message, you must clear the codes to get the compressor to start so you can add Freon. If you did that, and the compressor is running, but you still have no cold air, then you need to make sure that the A/C is cooling, then make sure that the programmer is working the temperature and vent control doors under the dash.

The stainless steel pipes coming out from the dashboard back into the compressor should be cold if the A/C is cooling. If not, there is a problem with the A/C that goes beyond low Freon. If the A/C *is* cooling, you need to make sure that the A/C controller under the dash is working OK; it needs both vacuum and a wiring harness connection. If it is having any problems, it will throw codes like the B0429.

[bkc928]

i never had a low freon message.how do i clear these messages,what am i looking for under the dash.looks kike some freon has leaked on the garage floor today also.

[Göran W]

If You have a visable freon leak it will very soon be empty! Go get it checked out!!!!!

[Cadillac Jim]

Freon is a gas and you won't see it leaking. If you have wet spots from something dripping on the garage floor, it is something else. If it's clear water that evaporates in a few hours, that's good news (unless it's been raining) because clear water is probably condensation from cooling in the A/C.

There are two ways to clear all the codes. One way is to disconnect the battery ground cable for a minute or two. The other is by using the car's computer. If you are using the A/C buttons <Off> and <Pass Warmer> together to read the OBD codes off your DIC (the message display on the dashboard), you are already using your car's computer. You get started by pressing <Off> and <Pass Warmer> together for a few seconds until all the dash lights come on like you just turned on the key, then release them both. The DIC will show the codes for each module, one at a time.

When the car's computer is done reading all the codes and displaying them, you will have a prompt "PCM ?" at which time you turn off the key if all you want to do is read the codes. At this point, you need to know that the <Off> button works like the escape key on your PC or Mac, and backs out one level of whatever is going on. For example, if you hit <Off> at the "PCM?" prompt, it will start over displaying all the codes. Another thing you need to know is that the fan rocker now is Up for "Yes" and Down for "No." So, if you answer the "PCM?" prompt with Fan Up, you will get another prompt, "PCM Codes?" Hit Fan Down and it will display "Clear PCM Codes?" at which time you hit Fan Up, and it will pause, then say "PCM Codes Cleared," then another PCM codes. Hit <Off> and it will back out of the PCM and go to the next module, which is IPC (instrument panel cluster). Hit Down until you get to ACM (A/C module) and hit Fan Up, then Fan Down until you see "Clear Codes?" then hit Fan Up. When it's done, you turn off the key.

[Logan]

I believe the B0429 issue is in the dash. The good news is the part can be changed by pulling the glove box. We are talking a 2001 Deville..right?