Test Description

WARNING: This page is about a different car, the 2006 GMC Yukon XL, 2006 GMC Yukon, 2006 Chevrolet Tahoe, 2006 Chevrolet Suburban, and 2006 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step numbers on the diagnostic table.

2: This step inspects for the visual operation of the Neutral indicator Light. Command both the ON and OFF states.
3: This step tests for voltage at the Neutral indicator feed side of the transfer case select switch.
4: This step verifies that the transfer case shift control module is providing ground to the Neutral indicator.
5: This step tests if ground is constantly being applied to the Neutral indicator.
6: This step tests the control circuit of the Neutral indicator for a short to voltage or an open.
7: This step tests the control circuit of the Neutral indicator for a short to ground.

DTC B0790

Step	Action	Yes	No
Schematic Reference: Transfer Case Control Schematics Connector End View Reference: Transfer Case Control Connector End Views
1	Did you perform the Diagnostic System Check - Vehicle?	Go to Step 2	Go to Diagnostic System Check - Vehicle
2	Install a scan tool. Turn the ignition ON, with the engine OFF. With the scan tool, command the Neutral Indicator Light ON and OFF. Does the Neutral Indicator Light turn ON and OFF with each command?	Go to Testing for Intermittent Conditions and Poor Connections	Go to Step 3
3	Turn the ignition OFF. Remove the transfer case select switch. Disconnect the connector on the transfer case select switch. Turn the ignition ON. Probe the ignition 3 voltage circuit with a DMM that is connected to a good ground. Does the DMM indicate battery voltage?	Go to Step 4	Go to Step 10
4	Connect a DMM between the harness connector of the neutral indicator control circuit and the ignition 3 voltage circuit. With the scan tool, command the Neutral indicator ON and OFF. Does the DMM indicate battery voltage and then 0 volts with each command?	Go to Step 8	Go to Step 5
5	Does the DMM continue to indicate battery voltage with each command?	Go to Step 7	Go to Step 6
6	Test the neutral indicator control circuit for a short to voltage or an open. Refer to Testing for Continuity and Wiring Repairs . Did you find and correct the condition?	Go to Step 13	Go to Step 9
7	Test the control circuit of the neutral indicator for a short to ground. Refer to Testing for Short to Ground and Wiring Repairs . Did you find and correct the condition?	Go to Step 13	Go to Step 9
8	Inspect for poor connections at the transfer case shift control switch. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring 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 transfer case shift 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 ignition 3 voltage circuit of the transfer case select switch for an open, a high resistance, or a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you complete the repair?	Go to Step 13	-
11	Replace the transfer case select switch. Refer to Transfer Case Shift Control Switch Replacement . Did you complete the repair?	Go to Step 13	-
12	Replace the transfer case shift control module. Refer to Control Module References for replacement, setup, and programming. Did you complete the repair?	Go to Step 13	-
13	Use the scan tool in order to clear the DTCs. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text. Does the DTC set?	Go to Step 2	System OK