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 provides an overview of each diagnostic category |
DTC Descriptor
DTC B3794 08: Cruise Control Function Request Circuit Signal InvalidDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
BCM B+ Terminal 3 | B3794 08, B1529 00, B3922 00 | B3794 08, B1529 00, B3922 00 | -- | -- |
BCM B+ Terminal 17 | B3794 08 B1529 00, B3922 00 | B3794 08 B1529 00, B3922 00 | -- | -- |
Cruise Control Switch Signal | B3794 08 | B3794 08 | B3794 08 | -- |
Circuit/System Description
The cruise control switch is an input to the body control module (BCM). The BCM monitors the cruise control on/off, set/coast, resume/accelerate and cancel switches via the cruise control 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 switch signal circuit when a switch is applied. The BCM sends a serial data message to the ECM indicating the status of the cruise control switches.
Conditions for Running the DTC
| • | Ignition ON. |
| • | Battery Voltage Must be Between 9 - 16 volts. |
Conditions for Setting the DTC
| • | The BCM detects a short to ground or open on the BCM B+ circuit. |
| • | The BCM detects a short to ground or short to voltage on the cruise control switch signal circuit. |
| • | The BCM detects an invalid voltage signal on the cruise control switch signal circuit. |
Actions Taken When the DTC Sets
| • | The malfunction indicator lamp (MIL) will not illuminate. |
| • | The cruise control system is disabled. |
Conditions for Clearing the DTC
| • | The condition responsible for setting the DTC no longer exists. |
| • | A history DTC will clear after 40 malfunction-free ignition cycles have occurred. |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Cruise Control Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Engine ON, observe the scan tool Cruise Control Switch parameter while pressing each of the cruise control switches. The parameter should toggle between On, Off, Resume and Set as the applicable switch is pressed.
Circuit/System Testing
- Ignition OFF, disconnect the X3 harness connector at the BCM.
- Verify that a test lamp illuminates between the BCM F9 fuse B+ circuit terminal 3 and ground.
- Ignition OFF, connect the X3 harness connector at the BCM.
- Disconnect the harness connector at the turn signal/multifunction switch.
- Ignition ON, test for B+ between the B+ circuit terminal 6 and ground.
- Ignition ON, test for B+ between the B+ circuit terminal 6 and the signal circuit terminal 5.
- Ignition ON, verify that a test lamp does not illuminate between B+ and the signal circuit terminal 5.
- If all circuits test normal, test or replace the turn signal/multifunction switch.
| ⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. |
| ⇒ | If less than the specified value, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM. |
| ⇒ | If less than the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM. |
| ⇒ | If the test lamp illuminates, test the signal circuit for a short to ground. If the circuit test normal, replace the BCM. |
Component Testing
- Disconnect the harness connector at the turn signal/multifunction switch.
- Cruise control switch ON, measure the resistance between terminal 5 and terminal 6 while individually activating and holding each cruise control function switch and compare the resistance reading to the values in the table below.
| ⇒ | If not within the specified resistance range, replace the turn signal/multifunction switch. |
Function Switch | Minimum Resistance Value | Maximum Resistance Value |
|---|---|---|
Off | 6.7k Ohms | 6.9k Ohms |
On | 1.4k Ohms | 1.6k Ohms |
- SET | 2.2k Ohms | 2.4k Ohms |
+ RES | 3.6k Ohms | 3.9k Ohms |
Repair Instructions
Perform the Diagnostic Repair Verification.
| • | Control Module References for BCM replacement, setup, and programming. |
