Circuit Description
The transmission range (TR) switch is part of the park/neutral position (PNP) and back-up lamp switch assembly, which is externally mounted on the transmission manual shaft. The TR switch contains four internal switches that indicate the transmission gear range selector lever position. The IPC supplies ignition voltage to each switch circuit. As the gear range selector lever is moved, the state of each switch may change, causing the circuit to open or close. An open circuit or switch indicates a high voltage signal in the IPC. A closed circuit or switch indicates a low voltage signal in the IPC. The IPC detects the selected gear range by deciphering the combination of voltage signals.
Diagnostic Aids
If all of the PRNDL indicators are inaccurate, ensure that the park neutral position switch is properly adjusted. Refer to Park/Neutral Position Switch Adjustment .
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Instrument Cluster Schematics DEFINITION: The transmission range selector display is inoperative or displays the incorrect gear selection. | ||||
1 | Did you review the Transmission Electronic Component Description and perform the necessary inspections? | -- | Go to Step 2 | |
2 |
Does the PRNDL indicate the correct gear in each position? | -- | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 |
3 | Are all of the PRNDL indicators inoperative? | -- | Go to Step 4 | Go to Step 6 |
4 | Test the off/run/crank voltage circuit for an open, for a high resistance or for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 5 |
5 | Test the park/neutral position switch ground circuit for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 6 |
6 |
Does the voltage measure at or near the specified value? | 10-12 Volts | Go to Step 7 | Go to Step 11 |
7 | Measure the voltage of the transmission range switch P signal circuit. Refer to Circuit Testing in Wiring Systems. Does the voltage measure near the specified value? | 10-12 Volts | Go to Step 8 | Go to Step 12 |
8 | Measure the voltage of the transmission range switch B signal circuit. Refer to Circuit Testing in Wiring Systems. Does the voltage measure near the specified value? | 10-12 Volts | Go to Step 9 | Go to Step 13 |
9 | Measure the voltage of the transmission range switch C signal circuit. Refer to Circuit Testing in Wiring Systems. Does the voltage measure near the specified value? | 10-12 Volts | Go to Step 10 | Go to Step 14 |
10 |
Do the inoperative PRNDL indicators illuminate? | -- | Go to Step 16 | Go to Step 15 |
11 | Repair the open, the high resistance or the short to ground in the transmission range switch A signal circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 17 | Go to Step 2 |
12 | Repair the open, the high resistance or the short to ground in the transmission range switch P signal circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 17 | Go to Step 2 |
13 | Repair the open, the high resistance or the short to ground in the transmission range switch B signal circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 17 | Go to Step 2 |
14 | Repair the open, the high resistance or the short to ground in the transmission range switch C signal circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 17 | Go to Step 2 |
15 | Replace the IPC. Refer to Instrument Cluster Replacement in Instrument Panel, Gages and Console. Is the repair complete? | -- | Go to Step 17 | Go to Step 2 |
16 | Adjust or replace the park/neutral position switch. Refer to Park/Neutral Position Switch Adjustment or to Park/Neutral Position Switch Replacement . Did you complete the repair? | -- | Go to Step 17 | Go to Step 2 |
17 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 2 |
