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B0104 GMC Code - Passenger-Side EFS Not Okay Message

- Code Popularity: 4,709 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 3/3
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What are the Possible Causes of the DTC B0104 GMC?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Faulty Passenger-Side Electronic Frontal Sensor (EFS)
  • Passenger-Side Electronic Frontal Sensor (EFS) harness is open or shorted
  • Passenger-Side Electronic Frontal Sensor (EFS) circuit poor electrical connection
  • Faulty Sensing and Diagnostic Module (SDM)
⚠ Does your GMC have Safety Recalls? → Check here

How to Fix the DTC B0104 GMC?

Review the 'Possible Causes' mentioned above and visually examine the corresponding wiring harness and connectors. Ensure to check for any damaged components and inspect the connector pins for signs of being broken, bent, pushed out, or corroded.

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What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B0104 GMC code, it typically requires 1.0 hour of labor. The specific diagnosis time and labor rates at auto repair shops can differ based on factors such as the location, make and model of the vehicle, and even the engine type. It is common for most auto repair shops to charge between $75 and $150 per hour.

What are Code Possible Symptoms?

  • Air Bag Warning Light ON

Code B0104 GMC Description

Electronic Frontal Sensor (EFS), also known as a front end sensor, uses a unidirectional 2-wire circuit. EFS sensor modulates current on the interface to send identification, State Of Health (SOH) and deployment commands to Sensing and Diagnostic Module (SDM). The SDM serves as a power source and ground for EFS. When ignition is turned on and EFS detects power from SDM, EFS responds by performing internal diagnostics and sending identification to SDM. SDM considers identification message to be valid if received within 5 seconds of EFS powering up. EFS continually communicates a status message to SDM. When fault is detected, SDM will attempt to reset EFS twice by removing and applying power. If fault is still present, SDM will set a Diagnostic Trouble Code (DTC).

OBDII Code B0104 GMC - Passenger-Side EFS Not Okay Message - AutoCodes.com
B0104 GMC Code - Passenger-Side EFS Not Okay Message

Need More Information on the Code?

Need more information on how to fix the B0104 GMC code? Get Access to Factory Service Manuals

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Precautions for SRS “AIR BAG” and “SEAT BELT PRE-TENSIONER” Service

  • Never probe the electrical connectors on air bag, side air curtain modules or seat belts.
  • Never disassemble or tamper with safety belt buckle/retractor pretensioners, adaptive load limiting retractors, safety belt inflators, or probe the electrical connectors.
  • Do not use electrical test equipment to check SRS circuits unless instructed to in this Service Manual.
  • Before servicing the SRS, turn ignition switch OFF, disconnect both battery cables and wait at least 3 minutes. For approximately 3 minutes after the cables are removed, it is still possible for the air bag and seat belt pre-tensioner to deploy. Therefore, do not work on any SRS connectors or wires until at least 3 minutes have passed.
Failure to follow this instruction may result in the accidental deployment of these modules, which increases the risk of serious personal injury or death.

Code B0104 GMC comments

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