B3623

DTC B3623

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview)provides an overview of each diagnostic category.



DTC Descriptors
DTC B3623 00
- Steering Wheel Controls Adaptive Cruise Control (ACC) Gap Up/Down Signal Circuit




Circuit/System Description

The body control module (BCM) monitors the adaptive cruise control (ACC) gap adjustment switch signal circuit to determine the driver selected headway. The gap switch is a momentary contact switch that connects a series of resistors. Each switch state, inactive, up and down, corresponds to a specific resistance value. The BCM determines the switch selection by the voltage drop across the resistor. The BCM sets DTC B3623 when it detects a stuck gap up/down switch.


Conditions for Running the DTC

Ignition is in RUN.


Conditions for Setting the DTC

Gap adjustment switch signal circuit remains in the same state for 1 minute.


Action Taken When the DTC Sets

Gap +/- switch remains in the last selected position.


Conditions for Clearing the DTC

* The DTC becomes history when the fault is no longer present.
* A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.



Reference Information
Schematic Reference

Cruise Control Schematics (Conventional) (Cruise Control Schematics (Conventional))Cruise Control Schematics (Adaptive) (Cruise Control Schematics (Adaptive))
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Cruise Control Description and Operation (Adaptive Cruise) (Cruise Control Description and Operation (Adaptive Cruise))Cruise Control Description and Operation (Conventional Cruise) (Cruise Control Description and Operation (Conventional Cruise))
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning)for scan tool information


Circuit/System Verification

Ignition ON, verify that the ACC Gap Switch parameter toggles accordingly between Up, Down and Inactive as the appropriate gap switch is pressed.


Circuit/System Testing

1. Ignition OFF, remove the inflatable restraint steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement (Service and Repair) .
2. Disconnect the harness connector at the steering wheel controls switch - left.
3. Ignition ON, test for 0 volts between the signal circuit terminal 2 and ground.

• If greater than the specified value, test the signal circuit terminal 2 for a short to voltage. If the circuit tests normal, replace the BCM.

4. Ignition OFF, connect the harness connector at the steering wheel controls switch - left.
5. Ignition ON, observe the scan tool ACC Gap Switch parameter. The parameter should display Inactive.

• If not the specified value, test or replace the steering wheel control switch - left.

6. Observe the scan tool ACC Gap Switch parameter while pressing the Gap Up portion of the ACC Gap switch. The parameter should display Up.

• If not the specified value, test or replace the steering wheel controls switch - left.

7. Observe the scan tool ACC Gap Switch parameter while pressing the Gap Down portion of the ACC Gap switch. The parameter should display Down.

• If not the specified value, test or replace the steering wheel controls switch - left.

8. If the circuits test normal, test or replace the BCM.



Component Testing


Steering Wheel Controls Switch - Left
1. Ignition OFF, remove the inflatable restraint steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement (Service and Repair) .
2. Ignition OFF, disconnect the harness connector at the steering wheel controls switch - left.
3. Measure the resistance between the supply voltage circuit terminal 1 and the signal circuit terminal 2. Individually activate and hold each gap function switch and compare the resistance reading to the values for the Gap Up, Gap Down, Cancel or the neutral position.

• If any of the resistance measurements for the Gap Up, Gap Down, Cancel or neutral position switches are not within the listed resistance values, replace the steering wheel controls - left.








Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Steering Wheel Control Switch Assembly Replacement (Service and Repair)
* Control Module References (Programming and Relearning)for BCM replacement, setup, and programming