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View Full Version : Check Control Message - what does it mean?



shogun
08-23-2009, 08:54 PM
this question came up from an E32 740 driver and there was a real easy to understand explanation:

Q: guys what does it mean when its appear on Cluster ?
second Question ? what is the Role of CCM ?

A:
Subject: Check Control Message, in simple terms...
Author: rv8flyboy Posted on: 2009-08-23


I get Check Control when the message stream between the CCM module and Cluster has a problem. Actually I got it quite a bit when i was developing my module to show oil temp and pressure in the cluster. If my message stepped on the CCM message, my cluster would get angry with me. I would only get it with the key in the run position.

Under normal conditions the CCM sends a stream of zero's and one's to the cluster every 100 Milliseconds. This stream is then compared in the cluster with a preset group of zero's and one's.

in simple terms every zero and one is associated with a stored warning or error message. As long as send string matches the stored string everything is happy, if a zero or one does not match, it's relative position in the bit stream is detected and a warning is displayed from a look-up table.

so, in simple terms the CCM module is an expansion module for the cluster. It checks things on the car in simple good/bad terms, as in switch ON, switch OFF, light ON, light OFF and passes this info to the cluster. The cluster then decides of it needs to display a message or not.

the cluster expects this CCM stream every 100 millisecs, if it don't get it it will display CHECK CONTROL.
750IL 1990 (9/89) Black, 75K,
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see page 28, 29 in owners manual
http://www.e38.org/e32/E32_1992_Owners_Handbook_Incl_V8_optimised.pdf
that means that there is apparently no communication between the check control module and the cluster. Pull the check control module, spray with contact cleaner and check proper seat of the module and insert it again, check if the communication comes back again.
Sometimes wiggling the CCM module helps to get contact again.