Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSPLYMOUTH1997PROWLER V6-3.5L VIN FREPAIR AND DIAGNOSISTRANSMISSION AND DRIVETRAINTRANSMISSION CONTROL SYSTEMSDESCRIPTION AND OPERATIONDIAGNOSTIC TROUBLE CODESTROUBLE CODE DESCRIPTIONS$21 (P1781) - OD PRESSURE SWITCH SENSE CIRCUIT
1997 Plymouth Prowler V6-3.5L VIN F
$21 (P1781) - OD Pressure Switch Sense Circuit
1997 Plymouth Prowler V6-3.5L VIN FSECTION $21 (P1781) - OD Pressure Switch Sense Circuit
Name of code: $21 (P1781) - OD Pressure Switch Sense Circuit
When monitored: Whenever the engine is running.
Set condition: This code is set if the OD pressure switch is open or closed at the wrong time in a given gear (see chart below).
Theory of operation: The Transmission system uses three pressure switches to monitor the fluid pressure in the L-R, 2-4, and OD clutch circuits. The pressure switches are continuously monitored for the correct states in each gear as shown below.
Transmission Effects: Normal operation will be experienced if no other fault codes are present. TCM will ignore the code. Limp-in and MIL illumination will only occur if code 21 (P1781) is present with a code 28(PO705).
Possible causes:
- If code 35(P1 791) is present, ignore code 21 (P1 781) and perform code 35(P1 791) diagnostic procedures
- OD pressure switch sense circuit open or shorted to ground between TCM and solenoid pack
- OD pressure switch sense circuit shorted to battery
- Solenoid pack defective
- Loose valve body bolts
- Plugged filter - internal transmission or torque converter failure
- Defective TCM
When monitored: Whenever the engine is running.
Set condition: This code is set if the OD pressure switch is open or closed at the wrong time in a given gear (see chart below).
Theory of operation: The Transmission system uses three pressure switches to monitor the fluid pressure in the L-R, 2-4, and OD clutch circuits. The pressure switches are continuously monitored for the correct states in each gear as shown below.
Transmission Effects: Normal operation will be experienced if no other fault codes are present. TCM will ignore the code. Limp-in and MIL illumination will only occur if code 21 (P1781) is present with a code 28(PO705).
Possible causes:
- If code 35(P1 791) is present, ignore code 21 (P1 781) and perform code 35(P1 791) diagnostic procedures
- OD pressure switch sense circuit open or shorted to ground between TCM and solenoid pack
- OD pressure switch sense circuit shorted to battery
- Solenoid pack defective
- Loose valve body bolts
- Plugged filter - internal transmission or torque converter failure
- Defective TCM
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.