GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provide overview of each diagnostic category.

DTC Descriptor

DTC B3794 5A: Cruise Control Select Switch Stuck

DTC B3794 08: Cruise Control Select Switch Resistance out of Range/Invalid

Circuit/System Description

The cruise control switch is an input to the steering column control module. The steering column control module monitors the cruise control set/coast, resume/accelerate switch signal circuit in order to detect when the driver has requested to perform a cruise control switch function. The steering column control module also detects a scheduled voltage signal on the cruise control Set/Coast and Resume/Accel switch signal circuit, indicating the On/Off switch is applied. The ECM receives the function request of the cruise control switch on serial data signal circuit.

Conditions for Running the DTC

    • The cruise control on/off switch is ON.
    • The ignition is ON.

Conditions for Setting the DTC

When one of the following conditions occurs, the steering column control module will set DTC B3794.

B3794 5A

The steering column control module detects that a cruise control select switch is activated on the cruise control set/coast and resume/accel switch signal circuit for more than 60 seconds.

B3794 08

The steering column control module detects that an out of range or invalid voltage signal on the cruise control set/coast and resume/accel switch signal circuit for more than 0.1 seconds.

Actions Taken When the DTC Sets

    • The steering column control module stores the DTC information into memory when the diagnostic procedure runs and fails.
    • The malfunction indicator lamp (MIL) will not illuminate.
    • The Cruise Control System is disabled.

Conditions for Clearing the DTC

    • The DTC becomes history when the conditions for setting the DTC are no longer present.
    • The history DTC clears after 50 ignition cycles without failure.
    • The steering column control module receives a clear code command from the scan tool.

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Cruise Control Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Ignition ON, observe the scan tool Engine, Data Display, Cruise Control Switch parameter. While pressing each of the cruise control switches, the parameter should display the current switch being pressed.

Circuit/System Testing

  1. Road test the vehicle and ensure the cruise control system functions normally and DTC B3794 does not set as current.
  2. If the DTC sets as current, replace the cruise control function switch and the steering column control module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References