Chart 7A-20A-4: PNP Switch Circuit

Diagnostic Chart - Part 1 Of 2:

Diagnostic Chart - Part 2 0f 2:

PNP Switch Circuit:

Circuit Description:
The PNP Switch sends individual gear position signals to the PCM according to manual selector lever position. When the manual selector lever is in "P" or "N," the PCM judges that the transaxle is in park or neutral. If the manual selector lever is in "R", "2" or "L," the PCM judges that the transaxle is in either reverse, second or low gear. With the manual selector lever in "D," the PCM does not receive a signal at all, and judges that the transaxle is in drive. These signals are used in conjunction with the shift solenoids to shift the transaxle electronically.

Test Description: Numbers below refer to circled numbers on the diagnostic chart.

1. This tests the PNP switch's P/N signal.

2. This determines if the cruise control module is preventing the transaxle from shifting into overdrive.

3. This tests the PNP switch's R position signal.

4. This checks for a faulty PNP switch or a faulty PCM.

5. This tests the PNP switch's 2 position signal.

6. This tests the PNP switch's L position signal.

Diagnostic Aids:
Check GAUGE Fuse for opens, and grounds for clean and tight connections. Also check for proper cruise control system operation.

Check for poor connections at component and inline harness connector terminal connections before replacing components. After repairs have been made, repeat the PCM OBD System Check to ensure system is functioning normally.