No SES during Diagnostics

[Mr. Anderson]

Now that I have the fog lights figured out, one of the last things that I have a question about is the SES light during diagnostics.

I know that the SES is supposed to flash based on being in closed or open loop, but the light does nothing while I am in diagnostic mode. I know the bulb isn't burned out because it lights when the key is turned to ON (engine off).

This does not effect the way the car runs or drives to my knowledge, and no codes are stored. What is the cause of this?

[KDirk]

I'll have to look, not sure if the SES does this on 91's or not. The 88 and 89 models do for certain, but somehow I think 90/91 don't as they use one of the icons in the climate panel display to indicate closed/open loop mode instead.

KDirk

[Ronnie]

I think my SES starts flashing as soon as you enter diagnostics and continues to do so until you exit. There is a triangle on the CRT that starts to flash to indicate closed loop operation.

Edited June 30, 2015 by Ronnie (see edit history)

[Mr. Anderson]

I'll have to look, not sure if the SES does this on 91's or not. The 88 and 89 models do for certain, but somehow I think 90/91 don't as they use one of the icons in the climate panel display to indicate closed/open loop mode instead.

KDirk

I know that my 90 convertible does the SES flashing during closed and open loop, but not sure about the 91.

[KDirk]

Well, the 89 and 90 use nearly identical ECM and BCM so that may make sense. 91 is a different system (engines and modules) so maybe that explains it. I will check the FSM and both my 91's to see how they respond and post back with my findings.

KDirk