U18CC GMC

Transmission Range Control Module Lost Communication With ECM On Powertrain Expansion Bus

Table of contents

• Possible Causes
• How To Fix
• Cost To Diagnose
• Possible Symptoms
• Description

U18CC GMC Possible Causes

• Faulty Engine Control Module (ECM)
• Engine Control Module harness is open or shorted
• Engine Control Module circuit poor electrical connection

How do I fix code U18CC GMC?

  Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.

Cost of diagnosing the U18CC GMC code

  The cost of diagnosing the U18CC GMC code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.

Possible Symptoms

• Engine Light ON (or Service Engine Soon Warning Light)

U18CC GMC Description

  Devices connected to the serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the devices. The devices have prerecorded information about what messages are needed to be exchanged on the serial data circuits, for each virtual network. The messages are supervised and also, some periodic messages are used by the receiver device as an availability indication of the transmitter device. Each message contains the identification number of the transmitter device. The Diagnostic Trouble Code (DTC) will set a supervised periodic message that includes the transmitter device availability that has not been received.