U2107 On Chevrolet and other GM vehicles with the GMLAN network, U2107 means the engine control module lost communication with the body control system

GM lost communication with body control module

U2107 in short

On Chevrolet and other GM vehicles, U2107 means the engine control module lost contact with the body control module. A GM bulletin lists it with power steering codes on 2005-2008 Cobalt and HHR models, and owners report lost steering assist. Have a dealer diagnose it soon; do not just clear it.

GM modules talk over a network. When the engine control module stops hearing the body control module, it stores U2107. The code names the missing link, not the failed part.

GM bulletin 07-02-32-007 lists U2107 with U2105 and several steering codes for a 2005-2008 Cobalt and HHR whose power steering stops working. A Corvette owner read U2100, U2105, U2107 and U2108 together with service messages after a recall repair, and a Cobalt owner reports lost power steering and the car losing power.

This page speaks only for Chevrolet; Ford also lists U2107 with a failure-type suffix in its own bulletins, but this page does not cover it.

Pick your make

U2107 is a manufacturer-specific code: its meaning depends on who built the car.

Other makes: meaning not verified. Check with a scan tool that reads manufacturer definitions.

Most likely causes

  1. Body control module fault or loss of its power or ground

    Common general cause
    Why it ranks here
    The reference lists the body control module, its power, ground and fuse as the usual causes of this GM code.
    What would change this
    Rises when other body functions fail too. Falls if the module responds on a scan tool.
    How to test the body control module (bcm)

  2. Wiring or another module disturbing the data line

    Common general cause
    Why it ranks here
    The reference lists a break in the data line or another module on the bus as a cause, and the Corvette owner read several lost-communication codes together.
    What would change this
    Rises when several lost-communication codes are stored. Falls if only U2107 is stored.

  3. Power steering system fault stored with the code

    Supported by vehicle data
    Why it ranks here
    GM bulletin 07-02-32-007 gives diagnostic tips for a power steering that stops working with U2107 set.
    What would change this
    Rises on Cobalt and HHR cars with steering messages. Falls if steering works normally.
    How to test the power steering control module

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Read all stored codes and note whether U2105, U2100, U2108 or power steering codes are stored with U2107.

    Low riskTool: scan tool that reads all modules

    • IfSteering codes are stored with it on a Cobalt, HHR or related car

      It meansFollow the GM bulletin route with a dealer.

      Go to step 2

    • IfSeveral lost-communication codes are stored

      It meansLook for a shared power, ground or wiring fault.

      Go to step 2

  2. Have a dealer check the body control module power and ground, network wiring and connectors, and the bulletin that fits the exact car.

    Best left to a shop

    Warning:Loss of power steering or drive power affects vehicle control; leave testing and repair to a trained technician.

Symptoms

  • Power steering message or hard steering Gets more serious: stop and have it checked.
  • Car loses power and must be restarted Gets more serious: stop and have it checked.
  • Traction control or active handling messages

How to fix

This is a safety-critical system, so we explain the code but don't give repair steps. Have it inspected by a qualified technician.

Parts and cost context

  • Power steering control module:GM bulletin summaries involve power steering codes; replacement should follow dealer diagnosis; labor varies; get a quote.

Labor varies by vehicle and shop; get a quote before you approve a repair.

Compare used part prices on PartPriceGuide

On your vehicle

Chevrolet

  • 070232007Status unverified

    Diagnostic tips for power steering inoperative, DTCs including U2105 and U2107

    2005–2008cobalt, hhr · issued · NHTSA 10022958

    Gives diagnostic tips for a power steering that stops working with those codes set. Only the NHTSA summary was read.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • U2100On Ford and Lincoln, U2100 means a module reports that its initial configuration is not complete

    Same system Supported by vehicle data

    U2100 was read with U2107 on a Corvette.

All Module network (CAN bus) communication codes

Sources and review

  1. GM 07-02-32-007 (NHTSA 10022958): power steering inoperative, DTCs including U2105 and U2107 — NHTSA (manufacturer communication)
  2. NHTSA complaint ODI 700186: 2005 Chevrolet Cobalt — NHTSA (owner complaint)
  3. NHTSA complaint ODI 841105: 2005 Chevrolet Corvette — NHTSA (owner complaint)
  4. U2107 code: what it means (Rick Muscoplat) — Rick's Free Auto Repair Advice
Last reviewed
Written by
Saurabh K.
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This page explains what a code usually means; it is not a substitute for a professional inspection. How we source and review · Report an error

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