I027

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

The Park/Neutral Position Switch is mounted on the transaxle assembly. It is a multi-signal switch which, among other things, sends information relative to gear selector position to the IPC. The PRND321 input consists of 4 discrete circuits to pull 4 IPC voltages LOW in various combinations to indicate each gear range. The voltage level of each of the circuits is represented as LOW = grounded circuit, HIGH open circuit. The 4 states displayed represent decoder A, B, C, and Parity (P) inputs respectively. The IPC transmits the 4 states to the PCM over serial data.

There are two parts to this diagnostic code definition. The first part results in the electronic PRND321 illuminating all display segments around each of the gear selections. If the ignition switch is in either the UNLOCK or RUN position, I034 (Loss of PCM Data) is not currently set, the PRND321 state as decoded by the IPC indicates Park or Neutral and the PCM does not indicate Park or Neutral, or vise versa, and this remains true for 6 seconds then the PRND321 display illuminates all display segments around each of the gear selections. If this condition continues for 3 seconds or more then DTC I027 is set current.

The second part to this diagnostic code definition involves the decoded PRND321 value equal to an invalid state. The table indicates all the valid PRND321 states. If the IPC's decoded value of the PRND321 inputs is not one of the states shown in the table and this condition remains true for.6 seconds then the PRND321 display illuminates all display segments around each of the gear selections. If this condition continues for 3 seconds or more then DTC I027 is set current.

TEST DESCRIPTION

Test numbers refer to circled numbers on the diagnostic chart.

1. 1D41 indicates the decoded value of the PRND321 inputs.

2. This test checks for an open in the ground circuit to the Park/Neutral Position Switch.

3. This test determines if the condition is caused by a problem with one of the inputs or the IPC.

TEST DESCRIPTION

Test numbers refer to circled numbers on the diagnostic chart.

1. Moving the Gear Selector Lever from PARK (P) to DRIVE (D) causes the state of each PRND321 circuit to change, thus indicating which circuit has a problem.

2. Disconnecting C102 removes the ground from the Park/Neutral Position Switch resulting in all PRND321 inputs indicating a HIGH state unless there is a short to ground on one of the circuits.