Circuit Description
Caution: Refer to SIR Caution in the Preface section.
Disable the inflatable restraint steering wheel module when performing this diagnostic table. Refer to SIR Disabling and Enabling in SIR.
The cruise control switch is an input to the body control module (BCM). The BCM monitors the cruise control set/coast and resume/accelerate switch signal circuit in order to detect when the driver has requested to perform a cruise control function. The BCM detects a specific voltage signal on the cruise control set/coast and resume/accelerate switch signal circuit when a switch is applied.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B3794 Cruise Control Function Request Circuit
Conditions for Running the DTC
| • | The cruise switch is ON. |
| • | The ignition is ON. |
Conditions for Setting the DTC
| • | The BCM detects an invalid voltage signal on the cruise control set/coast and resume/accelerate switch signal circuit. |
| • | The above condition is present for greater than 1 second. |
Action Taken When the DTC Sets
| • | The BCM stores the DTC information into memory when the diagnostic 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 fault is no longer present. |
| • | A History DTC clears after 100 malfunction-free ignition cycles. |
| • | The BCM receives a clear code command from the scan tool. |
Diagnostic Aids
| • | Rotate the steering wheel to both steering stops and activate each cruise control switch separately. With a scan tool, observe the Cruise Control Switch parameter in the BCM Cruise Control data list. This will help eliminate the possibility of a internally open or shorted inflatable restraint steering wheel module coil. |
| • | For an intermittent, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Cruise Control Schematics Connector End View Reference: Master Electrical Component List in Wiring Systems | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
Does the Cruise Control Switch parameter display Error? | -- | Go to Step 3 | Go to Step 4 | |
3 |
Does the Cruise Control Switch parameter display Error? | -- | Go to Step 9 | Go to Step 11 |
4 |
Does the Cruise Control Switch parameter display Error? | -- | Go to Step 7 | Go to Step 5 |
5 |
Does the Cruise Control Switch parameter display Error? | -- | Go to Step 7 | Go to Step 6 |
6 |
Does the Cruise Control Switch parameter display Error? | -- | Go to Step 7 | Go to Diagnostic Aids |
7 |
Important: The cruise control on/off switch must be turned ON in order to correctly view the set/coast switch and the resume/accel switch resistance values with the DMM.
Do the cruise control function switch resistance values measure between the specified values? | Off = O.L. On = 7.8 K-8.6 K Resume = 2.7 K-3.0 K Set = 1.2 K-1.3 K | Go to Step 8 | Go to Step 12 |
8 | Test the ignition 1 voltage circuit for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 10 |
9 | Test the cruise control set/coast and resume/accelerate switch signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 14 |
10 | Test the cruise control set/coast and resume/accelerate switch signal circuit for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 14 |
11 | Test the cruise control on switch signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 13 |
12 | Test the cruise control on switch signal circuit for a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 13 |
13 | Inspect for poor connections at the harness connector of the cruise control switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 15 |
14 | Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 16 |
15 | Replace the cruise control switch. Refer to Steering Wheel Control Switch Assembly Replacement in Steering Wheel and Column. Did you complete the replacement? | -- | Go to Step 17 | -- |
16 | Replace the BCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 17 | -- |
17 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
