Good Evening-

Several days after a recent front brake/rotor job (at the dealership) on my 2006 S60 AWD (81k miles), I noted a very slight jerk or hesitation while on the highway during my morning commute. I then noted (with a great deal of anxiety) that the "Stop Safely Brake Failure" warning appeared, alternating with and "Engine System Service Required" (ESSR) warning. The odometer read "-----". The dealership diagnosed a brake sensor (replaced) and diagnosed the ESSR warning as needing emissions work to replace the oil trap hose and clean the throttle body (I refused this work). Within 10 miles of driving, the same slight jerk/hesitation again happened and the alternating messages reappeared. The dealership wanted to replace the Brake Control Module (BCM) at $1400. I balked and did some research on this and first had them replace the battery (voltage was low) and then follow the TJ-5931 bulletin...no luck. The dealership then replaced the BCM...still no luck. They put my old (but obviously good) BCM back in my Volvo and replaced the Central Electronic Module (CEM). They road tested the car and all seems well...drove it home without issue. Unfortunately, I had to pick up my car after the service department closed so was unable to speak with the SM on what exactly the CEM is and how it contributed to the problem. I've googled but am unable to find any real info about this module.

I would appreciate any information. Also, do you think the bad CEM was the cause of the ESSR emissions codes as well?

Thanks-
Marie

 

Central Electronic Module (CEM)

Definition

• An electronic control module, also called an electronic control unit, is the embedded system used to control the functions of electrical systems contained within a motor vehicle. An embedded system is a computer system consisting of mechanical and hardware parts used to perform one or a few dedicated functions.
  
  

Function

• A car's electronic control module functions using closed-loop control, or a type of control scheme designed to monitor the outputs of a system in order to control inputs sent to the system. The electronic control module receives data via dozens of sensors in the car's electrical systems and performs calculations to determine such factors as the fuel-ignition timing and the time a fuel injector should remain open.
  
  

If you continue to have issues, go to this website they repair you ecm much cheaper that what it will cost you for a new one and it will have a lifetime warranty, they just repaired my DIM and it also has a lifetime warranty and it works like a new one from the dealer!

Central Electronic Module (CEM) for Volvo - Xemodex Inc. | Xemodex Inc.

I hope this helps you....repost and let us know

 

Patsfn2

Thx. for the apt description. It also controls mundane but neccessary things such as headlights. What bothers me is countless reports of Dealerships charging big money yet failing to fix faults. And forum users who fail to report conclusions to the detriment of all simarily affected owners.