Diagnostic Aids

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Yukon, 2002 Chevrolet Tahoe, 2002 Chevrolet Suburban, and 2002 Cadillac Escalade EXT. However, it is still accessible from the selected car via links, so may be relevant.

If the vehicle has not been reconfigured correctly or configured at all, the system may not enter and cycle through each of the power states correctly.
In the event the OnStar® system loses, or is temporarily removed from battery power, the sleep cycle will not begin until the vehicle passes into an open outside area where a GPS signal can be acquired, providing a reference for time.

OnStar Battery Consumption Test

Step	Action	Values	Yes	No
Schematic Reference: OnStar Schematics
1	Did you perform the Battery Electrical Drain/Parasitic Load Test?	-	Go to Step 2	Go to BATTERY ELECTRICAL DRAIN/PARASITIC LOAD TEST
2	IMPORTANT: It is important to have the vehicle in an open outside area where a cellular call can be successfully placed and GPS data can be received from satellites. It is also necessary to inform the OnStar® Call Center advisor that this call is for vehicle diagnostic purposes. Press the OnStar® Call Center button Ask the OnStar® Call Center advisor if the vehicle has been configured. Has the vehicle been configured?	-	Go to Step 4	Go to Step 3
3	Ask the OnStar® Call Center advisor to perform a Reconfiguration on the vehicle. Was the Reconfiguration successful?	-	Perform the Battery Electrical Drain/Parasitic Load test to verify whether the condition has been corrected by the Reconfiguration	Ask the OnStar® Call Center Advisor why the Reconfiguration was not successful and contact the General Motors Technical Assistance Center
4	Ask the OnStar® Call Center advisor if they have received GPS data. Has the OnStar® Call Center advisor received GPS data?	-	Go to Step 5	Go to Global Positioning System (GPS) Data Not Current or Inaccurate
5	Turn the ignition OFF Disconnect the VIU, connector C1 Remove the Battery Positive Voltage circuit from the connector at the Vehicle Interface Unit (VIU). Insert a fused jumper wire into the Battery Positive Voltage circuit cavity at the VIU connector Connect a DMM between the fused jumper from the VIU and the Battery Positive Voltage circuit. Set the DMM to the milli-amp scale. Reconnect VIU connector C1. Start the vehicle and move it to an open area where a GPS signal can be received. Allow the vehicle to run for 10 minutes. Observe the current draw reading of the DMM. Does the current draw measure greater than the specified value?	350mA	Go to Step 8	Go to Step 6
6	Turn the ignition OFF. Disable the Retained Accessory Power (RAP) function by opening and closing the driver door. Enable the MIN/MAX feature of the DMM. Allow the vehicle to remain parked with the ignition OFF for at least 30 minutes. Record the minimum and maximum values displayed on the DMM. Is the maximum current draw greater than the specified value?	300mA	Go to Step 8	Go to Step 7
7	Is the minimum current draw greater that the specified value?	.7mA	Go to Step 8	Go to Step 9
8	IMPORTANT: Perform the OnStar® setup procedure. Replace the VCU. Refer to OnStar Vehicle Communication Unit (VCU) Replacement . Did you complete the replacement?	-	Go to Step 10	-
9	IMPORTANT: Perform the OnStar® setup procedure. Replace the VIU. Refer to OnStar Vehicle Interface Unit (VIU) Replacement . Did you complete the replacement?	-	Go to Step 10	-
10	Perform the Battery Electrical Drain/Parasitic Load test in order to verify the repair. Did you correct the condition?	-	System OK	Go to Step 2