P0705

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

The transmission range 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 SETTING THE DTC

^ The PCM recognizes an invalid PRNDL parameter.

^ Vehicle speed is greater than 5 mph (8 km/h).

^ Above conditions met for greater than 5 seconds.

ACTION TAKEN WHEN THE DTC SETS

^ The PCM will record ope?ating conditions at the time the diagnostic fails. This information will be stored in the Failure Records buffer.

^ A history DTC is stored.

CONDITIONS FOR CLEARING THE MIL/DTC

^ A history DTC will clear after 40 consecutive warm up cycles without a fault.

^ DTC(s) can be cleared by using a scan tool.

DIAGNOSTIC AIDS

^ Monitor a scan tool while moving related connectors and wiring harness. If a failure is induced, the scan data will change states from either LO to HI, or from HI to LO. Moving the gear selector slowly through each gear while monitoring the scan tool may also help isolate the problem.

^ Any circuitry, that is suspected as causing the intermittent complaint, should be thoroughly checked for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wiring connections or physical damage to the wiring harness.

^ When a DTC P0705 is set, the PCM defaults to the 3rd gear until a correct combination is received by the PCM. Therefore, some selected gear positions may not be possible until the fault is repaired.

^ 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 - check for an open CKT 772.

- Reverse, Neutral, Overdrive and 3rd gear - check for a grounded CKT 772.

- Low, 2nd, 3rd and Overdrive gear - check for a grounded CKT 773.

- Park, Reverse, and Neutral - check for an open CKT 773.

- Park, Reverse, 2nd and 3rd gear - check for a grounded CKT 771.

- Neutral, Overdrive and Low gear - check for an open in CKT 771.

- Park, Neutral, 3rd and Low gear - check for a grounded CKT 776.

- Reverse 2nd and Overdrive gear - check for an open CKT 776.

TEST DESCRIPTION

Number(s) below refer to the step number(s) on the Diagnostic Table.

1. The Powertrain OBD System Check prompts the technician to complete some basic checks and store the freeze frame and failure records data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored on the scan tool for later reference.

4. Any circuitry, that is suspected as causing the intermittent complaint, should be thoroughly checked for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wiring connections or physical damage to the wiring harness.

5. An invalid circuit will cause the PRNDL display to go out. Jumpering each circuit to ground simulates the trans range switch operation and checks the circuitry and 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 faulty PCM.

9. Replacement PCM's must be reprogrammed. Refer to the latest Techline information for programming procedures.

11. If no faults have been found at this point and no additional DTC's were set, refer to Diagnostic Aids for additional checks and information.