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 .
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
This vehicle has DTCs which include DTC Symptoms.
DTC Symptom | DTC Symptom Descriptor |
|---|---|
08 | Signal Invalid |
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 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 Body and Accessories, BCM 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 . |
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 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 10 | Go to Step 14 |
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 16 | Go to Step 6 |
6 |
Does the Cruise Control Switch parameter display Error? | -- | Go to Step 16 | 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 9 | Go to Step 8 |
8 | Test the ignition 1 voltage circuit for a high resistance between C1 and the cruise control switch. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 11 |
9 | Test the ignition 1 voltage circuit for a high resistance between C1 and the BCM. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 13 |
10 | Test the cruise control set/coast and resume/accel switch signal circuit for a short to voltage between C1 and the BCM. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 17 |
11 | Test the cruise control on switch signal circuit for a high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 12 |
12 | Test the cruise control set/coast and resume/accel switch signal circuit for a high resistance between C1 and the cruise control switch. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 16 |
13 | Test the cruise control set/coast and resume/accel switch signal circuit for a high resistance between C1 and the BCM. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 17 |
14 | Test the cruise control set/coast and resume/accel switch signal circuit for a short to voltage between C1 and the cruise control switch. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 15 |
15 | Test the cruise control on switch signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 16 |
16 | Inspect for poor connections at the cruise control switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 18 |
17 | Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 20 | Go to Step 19 |
18 | Replace the cruise control switch. Refer to Steering Wheel Control Switch Assembly Replacement . Did you complete the replacement? | -- | Go to Step 20 | -- |
19 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 20 | -- |
20 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
