Circuit 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.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B3623 Steering Wheel Controls Adaptive Cruise Control (ACC) Gap Up/Down Signal Circuit.
DTC Symptom | DTC Symptom Descriptor |
|---|---|
00 | General Failure |
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 MIL/DTC
| • | The DTC becomes history when the fault is no longer present. |
| • | A History DTC clears after 100 malfunction free ignition cycles. |
| • | The BCM module receives a clear code command from the scan tool. |
Diagnostic Aids
Refer to Testing for Intermittent Conditions and Poor Connections .
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Cruise Control Schematics Connector End View Reference: Master Electrical Component List | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
2 |
Does the scan tool display voltage values at or near the specified values for the gap switch up, down, and inactive states? | Up-3.1 V Down-1.5 V Inactive-0 V | Go to Diagnostic Aids | Go to Step 3 |
3 |
Does the voltage measure greater than the specified value? | 4 V | Go to Step 4 | Go to Step 5 |
4 | Test the gap adjustment switch signal circuit for a short to voltage. Refer to Circuit Testing and to Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 6 |
5 | Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs . Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 7 |
6 | Inspect for poor connections at the harness connector of the steering wheel control switch assembly. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs . Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 8 |
7 |
Important: Perform the setup procedure for the replacement BCM. Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 9 | -- |
8 | Replace the steering wheel control switch assembly. Refer to Steering Wheel Control Switch Assembly Replacement . Did you complete the replacement? | -- | Go to Step 9 | -- |
9 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
