Tech Tip Tuesdays

TechTipTuesdays: CEM Communication Tips

CEM Communication Tips

Follow these steps to save yourself a lot of time and headaches. This is more of a #lifehack than a #techtip!

Before disassembling your CEM, make sure to take a photo of all your relays and shunts intact, prior to sending your unit in for repairs. This makes it easier when it comes time to install your unit back into your vehicle. You now have a visual representation and this ensures that the relays and shunts will go back to their correct positions.


  • I just bought my daughter a 2002 Volvo S60 T5. previous owner said they took it to a muffler shop to have an exhaust hanger welded back on, and they shorted the CEM they grounded to the car, not the exhaust. get alot of false codes in the information center when we first start the car, and left speakers in car will not work. also have issues with brake lights not working, until we bypassed them CEM. now when we hit the brakes, we get a brakelights warning on the information center. I’m thinking my CEM took a hit. How can I tell? if I send it in to you can you diagnose it? should I check the relays and fuses first in the CEM?

    • Hi Chris,
      I’ve forwarded your inquiry to our customer service department. They will be in touch with you shortly via email. Alternatively, you may contact us directly toll-free (US & Canadian customers) 1-888-712-2525 or email Thank you!

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