Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2009 Hummer H3 Base, AutomaticFACTORY OEM SERVICE PROCEDURE
Communication Interface Module Scan Tool Information
Vehicle Communication Interface Module Scan Tool Data Parameters
| Parameter | System State | Expected Value | Definition |
|---|---|---|---|
| Operating Conditions: Ignition ON | |||
| Date | - | Numeric | This displays DD/MM/YYYY. This is the date the VCIM was manufactured. |
| GPS Signal | - | Yes | The scan tool displays Yes or No. Yes is displayed if there is a GPS signal received by the VCIM. |
| Signal Strength | - | Varies | This displays a calculated value for cellular reception signal strength. A higher number indicates a stronger signal. |
| Signal Type | - | Digital | The scan tool displays Digital or Analog. This is the signal type received by the VCIM. |
| Time | - | Numeric | The scan tool displays HH:MM:SS. This is the current time. |
| Transceiver ID | - | Varies | The scan tool displays a 2-5 digit value. This displays the ID number of the cellular tower that the VCIM is using for cellular signal. |
Vehicle Communication Interface Module Scan Tool Output Controls
| Scan Tool Output Control | Description |
|---|---|
| B1000 Data | This shows the data recorded when DTC B1000 was set in the VCIM. |
| Green LED | The VCIM illuminates the green LED on the inside rearview mirror when ON is selected. |
| Phone Call Test | When ON is selected, VCIM commands OnStar to connect to the OnStar Center. |
| PRL Update | This function performs an update of the Preferred Roamer List. Provides a list of alternate networks to use when the service provider's and/or subscriber's primary wireless network cannot be reached. |
| Red LED | The VCIM illuminates the red LED on the inside rearview mirror when ON is selected. |
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.