Section 07-14B: Park/Neutral Position (PNP) Switch | 1996 F-150, F-250, F-350 4x2 and F-250, F-350 4x4 Vehicles Equipped with C6 Automatic Transmission Workshop Manual |
DIAGNOSIS AND TESTING
Pinpoint Tests
PINPOINT TEST A: ENGINE WILL NOT CRANK
A1 CHECK BATTERY
Is the battery OK?
| Yes | No |
|---|
| GO to A2. | CHARGE or REPLACE the battery. RETEST system. |
A2 CHECK PARK/NEUTRAL POSITION (PNP) SWITCH ADJUSTMENT
Is the park/neutral position switch adjusted properly?
| Yes | No |
|---|
| GO to A3. | ADJUST the park/neutral position switch. RETEST system. |
A3 CHECK START SIGNAL TO PARK/NEUTRAL POSITION (PNP) SWITCH
- Key off.
- Disconnect park/neutral position switch connector.
- Key in run.
- Measure the voltage of Circuit 33 (W/PK) wire at the park/neutral position switch connector.
Is the voltage greater than 10 volts with the key in the start position?
| Yes | No |
|---|
| GO to A4. | REFER to Section 11-05 to diagnose the ignition switch start position. |
A4 CHECK OPERATION OF PARK/NEUTRAL POSITION (PNP) SWITCH
- Remove the park/neutral position switch connector.
- Probe Circuits 33 (W/PK) and 32 (R/LB)
- Move the switch to the following positions. The following ohm values should be present at each:
- Park — Less than 5.0 ohms
- Reverse — Greater than 100k ohms
- Neutral — Less than 5.0 ohms
- Drive — Greater than 100k ohms
- Second (2) — Greater than 100k ohms
- First (1) — Greater than 100k ohms
Are the listed values present at each position?
| Yes | No |
|---|
| Park/neutral position switch OK. GO to A5. | REPLACE the park/neutral position switch. READJUST park/neutral position switch. REFER to Park/Neutral Position (PNP) Switch in the Adjustments portion of this section. RETEST system. |
A5 CHECK SIGNAL TO STARTER RELAY
- Key off.
- Reconnect park/neutral position switch connector.
- Disconnect starter motor connector.
- Place transmission in PARK.
- Key in run. Measure voltage of Circuit 33 (W/PK) at the starter relay.
Is the voltage greater than 10 volts?
| Yes | No |
|---|
| GO to A6. | SERVICE Circuit 32 (R/LB) for open. RETEST system. |
A6 CHECK SIGNAL TO STARTER MOTOR
- Key off.
- Transmission in PARK.
- With key in run, measure voltage of (R) wire at the starter motor.
Is the voltage greater than 10 volts?
| Yes | No |
|---|
| REFER to Section 03-06A for starter motor diagnostics. | SERVICE (R) wire for open. RETEST system. |
PINPOINT TEST B: ENGINE CRANKS WITH TRANSMISSION RANGE SELECTOR LEVER IN RANGES OTHER THAN PARK OR NEUTRAL
B1 TRANSMISSION RANGE SELECTOR LEVER CHECK
- Check to make sure the park/neutral position switch harness is fully seated and in good condition.
- Verify park/neutral position switch is in aligning notches.
- Adjust the park/neutral switch alignment tool until all three notches are in alignment.
- Bolt park/neutral position switch to transmission.
- Using Rotunda 73 Digital Multimeter 105-R0051 or equivalent, check Circuit 32 (R/LB) of the PNP switch, place ignition switch in the START position. See if there is voltage at Circuit 32 (R/LB) in any other position than PARK or NEUTRAL.
Is there voltage at the switch in positions other than PARK or NEUTRAL?
| Yes | No |
|---|
| GO to B2. | System OK. |
B2 CHECK CIRCUIT 32 (R/LB) FOR POWER
- Access Circuit 32 (R/LB) at the park/neutral position switch.
- Using Rotunda 73 Digital Multimeter 105-R0051 or equivalent, check Circuit 32 (R/LB) at the park/neutral position switch with the key in run. Move the park/neutral position switch through the full range.
Is there voltage in any position other than PARK or NEUTRAL?