Range Selector Displays Incorrect Range

Range Selector Displays Incorrect Range





Circuit Description
The transmission range (TR) switch is part of the park/neutral position and back-up lamp switch assembly and is mounted on the transmission manual shaft. The TR switch is a multi-signal switch. The TCM monitors voltage on the four TR switch signal circuits, A, B, C, and P. Each gear selector lever position supplies voltage to one or more of the signal circuits in a unique pattern. In order to determine the gear range selected by the driver, the TCM compares the voltage combination on the signal circuits to a TR switch combination table stored in memory.

Diagnostic Aids
Refer to Transmission Range Switch Logic for valid combinations of switch signal circuits A, B, C and P.

Test Description
The numbers below refer to the step numbers on the diagnostic table.
4. By disconnecting the TR switch, the voltage path for all TR switch circuits would be removed and the TCM should recognize all circuits as open. The scan tool should display LOW for all range signals.
5. This step tests the TR switch wiring for an open or lack of ground from the TCM.
6. This step tests the TR switch wiring and the TCM by providing a voltage path through a fused jumper wire. When jumpered, the scan tool range signal A should change to HI.
7. This step tests the TR switch wiring and the TCM by providing a voltage path through a fused jumper wire. When jumpered, the scan tool range signal B should change to HI.
8. This step tests the TR switch wiring and the TCM by providing a voltage path through a fused jumper wire. When jumpered, the scan tool range signal C should change to HI.