Circuit Description
The transmission range switch, which is part of the park/neutral position (PNP) switch, is a multi-signal switch which sends a signal to the PCM to indicate gear selection. The transmission range switch uses 4 discrete circuits to pull 4 PCM voltages low in various combinations to indicate each gear range. The voltage level of the circuits is represented as LO = grounded, HI = open circuit. The 4 states displayed represents the encoder P, A, B, and C inputs in sequence.
Conditions for Running the DTC
| • | The PCM recognizes an invalid PRNDL parameter. |
| • | The vehicle speed is more than 5 mph (8 km/h). |
Conditions For Setting the DTC
The above conditions met for a period longer than 5 seconds.
Action Taken When the DTC Sets
| • | The PCM will record operating conditions at the time during which the diagnostic fails. This information will store in the Failure Records buffer. |
| • | A history DTC stores. |
Conditions for Clearing the MIL/DTC
| • | A history DTC will clear after 40 consecutive warm up cycles without a fault. |
| • | Use a scan tool to clear the DTCs. |
Diagnostic Aids
| • | Monitor a scan tool while moving the related connectors and the wiring harness. If a failure is induced, the scan data will change states from either LO to HI, or from HI to LO. Move the gear selector slowly through each gear while monitoring the scan tool in order to help isolate the problem. |
| • | Thoroughly inspect any suspected circuitry for the following conditions: |
| - | Improper mating |
| - | Broken locks |
| - | Improperly formed or damaged terminals |
| - | Poor terminal to wiring connections |
| - | Physical damage to the wiring harness |
| • | When a DTC P0705 sets, the PCM defaults to the 3rd gear until the PCM receives a correct combination. Therefore, some of the selected gear positions may not be possible until you repair the fault. |
| • | If the trans range switch on the scan tool and the PRNDL on the IPC display a normal reading only in the following gear selections: |
| - | Park, Low, and 2nd gear -- Test for an open in the TR switch input B circuit. |
| - | Reverse, Neutral, Overdrive and 3rd gear -- Test for a grounded TR switch input B circuit. |
| - | Low, 2nd, 3rd and Overdrive gear - Test for a grounded in the TR switch input C circuit. |
| - | Park, Reverse, and Neutral -- Test for an open in the TR switch input C circuit. |
| - | Park, Reverse, 2nd and 3rd gear --- Test for a grounded in the TR switch input A circuit. |
| - | Neutral, Overdrive and Low gear -- Test for an open in the TR switch input A circuit. |
| - | Park, Neutral, 3rd and Low gear -- Test for a grounded in the TR switch input P circuit. |
| - | Reverse 2nd and Overdrive gear -- Test for an open in the TR switch input P circuit. |
Gear Selector Position | Scan Tool Trans Range PABC Display | |||||
|---|---|---|---|---|---|---|
4 Spd | 3 Spd | P | A | B | C | |
Park | P | P | LO | LO | HI | HI |
Reverse | R | R | HI | LO | LO | HI |
Neutral | N | N | LO | HI | LO | HI |
Drive | OD | D | HI | HI | LO | LO |
Drive | 3 | 2 | LO | LO | LO | LO |
Drive | 2 | 1 | HI | LO | HI | LO |
Drive | 1 | -- | LO | HI | HI | LO |
Test Description
The numbers below refers to the step numbers on the diagnostic table:
-
An invalid circuit will cause the PRNDL display to go out. Connecting a jumper wire to each circuit to ground simulates the park/neutral position switch operation, and tests the circuitry and the PCM. While the trans range switch is disconnected and the circuits are not jumpered to ground, the scan tool should indicate a HI value. A value that is indicated as LO with no jumper to ground indicates a grounded circuit or a malfunctioning PCM.
-
The replacement PCM must be programmed and the Crankshaft Position System Variation Learn procedure must be performed.
Step | Action | Values | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||||||
2 |
Does the scan tool indicate an invalid in any of the ranges? | -- | Go to Diagnostic Aids | |||||
3 | Compare the scan tool values with the Park/Neutral Position Switch Valid Input Combinations table above. Are all of the circuits indicated as HI? | -- | ||||||
4 |
Did you find and correct the condition? | -- | ||||||
Does the jumpered circuit go from a HI value to a LO value? | -- | |||||||
6 |
Did you find and correct the condition? | -- | ||||||
7 |
Did you find and correct a condition? | -- | ||||||
8 |
Did you complete the replacement? | -- | -- | |||||
|
Important:: The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Did you complete the replacement? | -- | -- | ||||||
10 |
Does the DTC reset? | -- | System OK |
