AC light flashing?
Thread Starter
Race Director
Joined: Oct 2011
Posts: 16,097
Likes: 821
From: Dallas Texas
2025 C4 of the Year Finalist - Modified
AC light flashing?
While doing a scan on my 93 C4 LT1, the AC light was blinking. Turned the car off for about two minutes. Started it again, and the light wasn't flashing anymore. I disconnected the datalog, if that has anything to do with it. Also, when the light wasn't blinking, I turned the AC on and it blew cold. Any ideas why it started flashing?
Thread Starter
Race Director
Joined: Oct 2011
Posts: 16,097
Likes: 821
From: Dallas Texas
2025 C4 of the Year Finalist - Modified
Thanks bud! I see you are in the DFW. Are you going to C&C in Plano on Saturday. Anyways, I've been emailing the owner of 1320electronics(John) and he's been a big help. I told him that the AC auto light flashes when I connect the scan. Here's his response in my email
"Hi Mr. Herrera-
The A/C light and ABS doing that I suspect is normal. The A/C and ABS share the bus with the ECM and CCM. The CCM runs the show. To communicate with the ECM, you have to shut down the CCM. When that happens, the ABS and A/C are just indicating that they have lost communication with the CCM. In the future, we can write adx files to communicate with the CCM, ABS, and A/C to get the info out of them too!"
"Hi Mr. Herrera-
The A/C light and ABS doing that I suspect is normal. The A/C and ABS share the bus with the ECM and CCM. The CCM runs the show. To communicate with the ECM, you have to shut down the CCM. When that happens, the ABS and A/C are just indicating that they have lost communication with the CCM. In the future, we can write adx files to communicate with the CCM, ABS, and A/C to get the info out of them too!"
Race Director
Joined: Mar 2015
Posts: 15,926
Likes: 579
Thanks bud! I see you are in the DFW. Are you going to C&C in Plano on Saturday. Anyways, I've been emailing the owner of 1320electronics(John) and he's been a big help. I told him that the AC auto light flashes when I connect the scan. Here's his response in my email
"Hi Mr. Herrera-
The A/C light and ABS doing that I suspect is normal. The A/C and ABS share the bus with the ECM and CCM. The CCM runs the show. To communicate with the ECM, you have to shut down the CCM. When that happens, the ABS and A/C are just indicating that they have lost communication with the CCM. In the future, we can write adx files to communicate with the CCM, ABS, and A/C to get the info out of them too!"
"Hi Mr. Herrera-
The A/C light and ABS doing that I suspect is normal. The A/C and ABS share the bus with the ECM and CCM. The CCM runs the show. To communicate with the ECM, you have to shut down the CCM. When that happens, the ABS and A/C are just indicating that they have lost communication with the CCM. In the future, we can write adx files to communicate with the CCM, ABS, and A/C to get the info out of them too!"
Try Cliff's trick it is what I was talking about. 
