The cruise control switch is an input to the instrument panel module (IPM). The IPM monitors the cruise control set/coast, resume/accelerate switch signal circuit in order to detect when the driver has requested to perform a cruise control switch function. The IPM also detects a scheduled voltage signal on the cruise control Set/Coast and Resume/Accel switch signal circuit, indicating the On/Off switch is applied. The ECM receives the function request of the cruise control switch on GMLAN serial data signal circuit.
The diagnostic procedure supports the following DTCs:
DTC B3794 Cruise Control Function Request Circuit
The vehicle has DTCs including the DTC symptoms. For more information on DTC symptoms, refer to DTC Symptom Description .
DTC Symptom | DTC Symptom Descriptor |
---|---|
01 | Short to B+ |
08 | Signal Invalid |
59 | Overtime Circuit/Component Protection |
• | The cruise control on/off switch is ON. |
• | The ignition is ON. |
When one of the following conditions occurs, the IPM will set DTC B3794.
The IPM detects that a high voltage signal on the cruise control set/coast and resume/accel switch signal circuit for more than 5 seconds.
The IPM detects that an invalid voltage signal on the cruise control set/coast and resume/accel switch signal circuit.
The IPM detects that a voltage signal on the cruise control set/coast and resume/accel switch signal circuit for more than 60 seconds.
• | The IPM stores the DTC information into memory when the diagnostic procedure runs and fails. |
• | The malfunction indicator lamp (MIL) will not illuminate. |
• | The Cruise Control System is disabled. |
• | The DTC becomes history when the conditions for setting the DTC are no longer present. |
• | The history DTC clears after 50 ignition cycles without failure. |
• | The IPM receives a clear code command from the scan tool. |
The following are the correct switch resistance value range and readings displayed as the cruise control parameters when the switches are pressed one by one in the Body and Accessory/Cruise Control/IPM/Input Data List. If no switch is pressed, the resistance value should be infinite.
Switch Function | Resistance Value Range (Ω) | Counts |
---|---|---|
OFF | O.L. | 0 |
On | 7.8-8.6K Ω | 29 |
Resume | 2.7-3.0K Ω | 76 |
Set | 1.2-1.3K Ω | 148 |
• | Make sure the Set/Coast or Resume/Accel switch has not been stuck in the ON position. |
• | If there is intermittent condition, 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 | Have you conducted Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
2 |
Is the cruise control display equal to or greater than the specified value? | 35 Counts | Go to Step 5 | Go to Step 3 |
3 |
Is the measured voltage within the specified value? | B+ | Go to Step 4 | Go to Step 10 |
4 |
Important: The cruise control on/off switch must be turned ON in order to correctly view the set/coast switch resistance value with the DMM.
Is the measured resistance of the cruise control function switch within the specified value? | Off = O.L. On = 7.8-8.6K Resume = 2.7-3.0K Set = 1.2-1.3K | Go to Step 7 | Go to Step 8 |
5 |
Important: The cruise control on/off switch must be turned ON in order to correctly view the set/coast switch resistance value with the DMM.
Is the measured resistance of the cruise control function switch within the specified value? | Off = O.L. On = 7.8-8.6K Resume = 2.7-3.0K Set = 1.2-1.3K | Go to Step 6 | Go to Step 8 |
6 | Test the cruise control set/coast and resume/accel. switch signal circuit for a short to the voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 9 |
7 | Test the cruise control set/coast and resume/accel. switch signal circuit for high resistance. Refer to Circuit Testing and Wiring Repairs . Is the repair complete? | -- | Go to Step 13 | Go to Step 9 |
8 | Inspect for poor connections at the multifunction switch C2. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 11 |
9 | Inspect for poor connections at the harness connector of the body control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 12 |
10 | Repair the high resistance in the ignition 1 voltage circuit. Refer to Circuit Testing and Wiring Repairs . Is the repair complete? | -- | Go to Step 13 | -- |
11 | Replace the cruise control switch. Refer to Turn Signal Multifunction Switch Replacement . Have you finished the replacement? | -- | Go to Step 13 | -- |
12 | Replace the body control module. Refer to Control Module References for replacement, setup, and programming. Have you finished the replacement? | -- | Go to Step 13 | -- |
13 |
Does the DTC set again? | -- | Go to Step 2 | System OK |