• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Keypad Supply Voltage | B2476 00 | B2476 00 | B2476 00 | -- |
Keypad Green LED Signal | 1 | 1 | 2 | -- |
Keypad Red LED Signal | 1 | 1 | 2 | -- |
Keypad Signal | 3 | 3 | -- | B2482 00 |
Button Assembly Ground | -- | 1 | -- | -- |
1. OnStar® LED(s) Inoperative 2. LED illuminated at all times 3. OnStar® Buttons Inoperative |
The OnStar® button assembly consists of 3 buttons, Call/Answer, OnStar® Call Center, and OnStar® Emergency. The communication interface module (CIM) supplies the OnStar® button assembly with 10 volts via the keypad supply voltage circuit. Each of the buttons, when pressed, completes the circuit across a resistor allowing a specific voltage to be returned to the CIM over the keypad signal circuit. Depending upon the voltage range returned, the CIM is able to identify which button has been activated.
• | Circuit Testing |
• | Wiring Repairs |
Control Module References for scan tool information
Important: Contact the OnStar® Call Center first before pressing the emergency button in order to notify them of the test.
Ignition ON, press the OnStar® Call buttons one at the time. Verify that all of the OnStar® buttons operate normally.
⇒ | If some OnStar® buttons are inoperative but not all, replace the inside rearview mirror. |
⇒ | If none of the OnStar® buttons operate, refer to circuit/system testing. |
⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
⇒ | If greater than the specified range, test the keypad signal circuit for a short to voltage. If the circuit tests normal, replace the CIM. |
⇒ | If less than the specified range, test the keypad signal circuit for a short to ground. If the circuit tests normal, replace the CIM. |
⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. If the circuit tests normal, replace the CIM. |
⇒ | If less than the specified range, test the supply voltage circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the CIM. |
⇒ | If greater than the specified range, test the supply voltage circuit for a short to voltage. If the circuit tests normal, replace the CIM. |
⇒ | If less than the specified range, replace the button assembly. |
⇒ | If not within the specified range, replace the button assembly. |
⇒ | If not within the specified range, replace the button assembly. |
⇒ | If not within the specified range, replace the button assembly. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for CIM replacement, setup, and programming |