All You Need To Know About A Volvo CEM Programming

A Volvo CEM programming is a necessity when it comes to a few important situations. 

For the most part, it happens when your CEM is showing signs of damage. So, it is essential to take note of these conditions, which will enable you to make necessary preparations before it is too late.

Today, we’ll talk about the common reasons why a CEM would need programming and what you can do about it. Let’s get right into it.

volvo cem programming

Volvo CEM Programming

First of all, you need to have your CEM programmed because of two reasons. One, if there is no brand new software loaded, and second, if you have the wrong software loaded in your vehicle. There is still a debate on loading a different software, yet there is a consensus that this can be done without any problem at all.

If your CEM comes with a faulty connector, you should be able to swap your connector from used working units to a malfunctioning one with a similar connector that you previously had issues with. However, this is only possible when your unit still functions but not the connectors. Keep in mind that your connector does not store any software.

With all these things in mind, you have the CEM where you also have bad CSH1 and CSH2 connectors. In case you are skilled with soldering, then you can also move these connectors from your donor unit to another unit. You should not have any issue doing this, as long as you are aware that the connectors are the only problems and nothing more.

Now, if you decide to swap the entire CEMs, then you should only be able to do so when it is the same model part number and year number. But the only drawback with this is that your CEM tends to take up the most mileage portion. This is why it is always a practical approach for you to look for a CEM that comes with a lower mileage than your vehicle.

The end result shows your vehicle’s actual mileage. This typically works well because the dealer should have already installed the right and most recent software. But then again, this does not always work this way, since there are a few vehicles that tend to slip right through the cracks. 

Also, it is worth noting that the software versions tend to be identical, and yet the information is placed on the CEM. Thus, you can’t have it swapped out because of some programming involved. Moreover, when your VIN stored on your CEM is different from the VIN on your windscreen or body of your vehicle, this will not work. This is actually a blessing in disguise and dealers won’t be able to reload used CEMs because it is not allowed.

If you decide to buy used CEMs these early models will have to be shorted. In this case, your programmer will be able to access the vehicle with a Dice diagnostic tool using internet connection. 

Read More: Common Volvo ECU Problems You Never Knew

Problems With The CEM

Some people complain about a portion inside their CEM being broken, and they do not have power in their left turn signals. Thus, they wonder if it is fine to get a brand new connector. And if this is the case, they assume it is possible to solder it back to their CEM.

Furthermore, they inquire about the possibility of buying a CEM and having to program it to their vehicle. Or if there is a need to program this component and swap out their old one for a brand new one without any additional programming required.

The best way to go about it is by pairing your CEM with the ECU depending on the model or year. Your CEM comes with relays that tend to burn out. However, some services can rebuild the unit, and this prevents the need for pairing done by your dealer. 

Now as for the common issues with the CEM, there are certain vehicles that are most commonly affected by this issue. This includes the Volvo XC90, S60, S80, V70, and the XC70. 

Among the faults typical with problematic CEMs are:

  • The windscreen wipers acting up
  • Failure with illumination
  • Zero communication
  • The fuel pump relay does not work
  • Lack of a +12 volt output from your CEM to the BCM
  • Water damage that causes intermittent faults

When you have a failing CEM, the unit tends to overheat and then shut down. This will then cut power off to your vehicle and lead to starting problems. The only way to be able to start is once your CEM module has cooled down or you have replaced your broken one with a brand new part. There are also some models that have issues with clogged water drains, which cause the water to overflow onto their CEM. Hence, the CEM tends to fail because of corrosion and rust over time.

2 thoughts on “All You Need To Know About A Volvo CEM Programming”

  1. The main problem with this 2005 XC90 T6 CEM is that it doesn’t sleep. It continues to provide 12V to the fuses under the hood and causes a 400ma draw. Sounds like a hardware problem. There is no water damage. I can’t seem to find the correct one CEM M 12217779.
    Any advice? Thanks! Dean

    • It sounds like there may be an issue with the CEM (Central Electronic Module) in your 2005 XC90 T6. The CEM is responsible for controlling many of the electronic systems in the car, including the power distribution to the fuses.

      If the CEM is not allowing the car to enter sleep mode, it could be causing the continuous 12V power supply and the 400ma draw you are experiencing. This could be a hardware problem with the CEM itself, and it may need to be replaced.

      The part number you provided, CEM M 12217779, appears to be a valid part number for the CEM in your XC90. However, it’s always best to double-check with a certified Volvo technician or dealership to ensure you are purchasing the correct part for your specific vehicle.

      If you’re having trouble finding the correct part or resolving the issue with the CEM, it may be best to seek the help of a professional mechanic or Volvo specialist who can diagnose and repair the problem for you.


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