hvac

AC Pressure Sensor

for 2017 Dodge Viper 8.4L V10 · RWD

Difficulty

Easy

Time

36 min

Tools

Steps

✓Fact-checked. Built from OLP's spec database, then independently fact-checked line by line with every correction applied. Master-tech sign-off by Chris Hackleman is queued. Cross-check torque values against the factory manual, and stop if anything looks unsafe. How our data is made.

Replace the AC pressure sensor on a 2008 Dodge Viper 8.4L V10 to restore proper air conditioning system pressure monitoring and compressor cycling control.

Warnings

⚠️AC refrigerant must be recovered by a certified technician using approved equipment. Venting refrigerant to atmosphere is illegal and environmentally harmful.

⚠️Wear safety glasses and gloves. Refrigerant contact with skin can cause frostbite, and contact with eyes can cause serious injury.

⚠Do not allow moisture or contaminants to enter the AC system during sensor replacement. Cap all open fittings immediately.

ℹ️The AC system must be properly evacuated and recharged after sensor replacement. Refrigerant capacity should be verified against the underhood HVAC specification label.

Tools required

AC refrigerant recovery machineEssential

Ratchet and socket setEssential

Refrigerant manifold gauge setEssential

Vacuum pumpEssential

Safety glassesEssential

Work glovesEssential

Clean shop towels

AC leak detector (electronic or UV)

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Parts

AC pressure sensor (transducer) × 1 — Use OEM specification
AC pressure sensor O-ring × 1 — Use OEM specification or included with sensor

As an Amazon Associate and Autel/ANCEL partner, OLP earns from qualifying purchases — how we link. This never changes the specs we publish.

Fluids

R-134a

Preparation

Park vehicle on level surface and apply parking brake
Turn off engine and allow to cool if recently operated
Ensure AC refrigerant recovery machine is properly connected and functional
Locate the AC pressure sensor on the liquid line near the condenser on the driver side of the vehicle

Procedure

1
Recover refrigerant from AC system
Connect the AC refrigerant recovery machine to the vehicle's service ports. Follow the machine manufacturer's instructions to completely recover all R-134a refrigerant from the system. Record the amount of refrigerant recovered for proper recharge later. Ensure the system is fully depressurized before proceeding.
2
Disconnect battery negative terminal
Disconnect the negative battery cable to prevent electrical shorts and stored trouble codes during sensor replacement. Move the cable away from the battery terminal.
3
Locate AC pressure sensor
The AC pressure sensor is typically mounted on the high-side/liquid line near the condenser. Verify the exact location and mounting style (threaded fitting vs. Schrader-base snap-in transducer) against the factory service information for this vehicle, as it affects the removal method. The sensor has a single electrical connector.
4
Disconnect electrical connector
Press the release tab on the AC pressure sensor electrical connector and carefully pull the connector straight off the sensor. Inspect the connector pins for corrosion or damage.
5
Remove AC pressure sensor
Using a socket or wrench, unscrew the AC pressure sensor from the refrigerant line fitting. Turn counterclockwise to remove. Immediately cap or plug the open port in the refrigerant line to prevent moisture and contaminant entry. Remove and discard the old O-ring seal from the sensor port.
6
Prepare new sensor for installation
Inspect the new AC pressure sensor threads and sealing surface for damage. Install the new O-ring onto the sensor, lightly lubricating it with clean refrigerant oil if provided. Do not use petroleum-based lubricants on AC system components.
7
Install new AC pressure sensor
Remove the cap from the refrigerant line port. Thread the new AC pressure sensor into the line fitting by hand until finger-tight. Tighten the sensor to the factory-specified torque per the service manual for this vehicle. Do not overtighten as this can damage the sensor or fitting. (If the sensor is a snap-in Schrader-base type, seat it fully per the manufacturer's instructions rather than tightening by rotation.) Do not overtighten as this can damage the sensor or fitting.
8
Reconnect electrical connector
Push the electrical connector onto the new AC pressure sensor until the locking tab clicks into place. Gently tug on the connector to verify it is securely attached.
9
Reconnect battery
Reconnect the negative battery cable to the battery terminal and tighten securely.
10
Evacuate AC system
Connect a vacuum pump to the AC service ports. Evacuate the system for a minimum of 30 minutes to remove all air and moisture. Monitor vacuum gauge for proper vacuum level and hold. If the system does not hold vacuum, check for leaks at the new sensor installation.
11
Recharge AC system
Using the refrigerant manifold gauge set and charging equipment, recharge the AC system with the correct amount of R-134a refrigerant as specified on the underhood HVAC label for this vehicle. Add refrigerant through the low-side service port with the engine running and AC on maximum cooling.

Reassembly

Verify all electrical connections are secure and properly seated
Confirm refrigerant line fittings show no signs of refrigerant oil leakage
Check that all tools and shop towels have been removed from the engine compartment

Verification

Start the engine and turn the AC system on to maximum cooling
Verify the AC compressor engages and cycles properly
Check that cold air is produced from the vents within 1-2 minutes
Use an AC leak detector to check the pressure sensor installation for leaks
Monitor AC system performance for proper cooling over a 10-15 minute test drive
Verify no AC-related diagnostic trouble codes are present using a scan tool
Confirm system pressures are within specification using manifold gauges (typically 25-45 psi low side, 200-250 psi high side at idle with ambient temperature 70-80°F)