AC Low Pressure Switch

This procedure covers the removal and replacement of the AC low pressure switch on a 2023 Chevrolet Bolt EUV, including refrigerant recovery and system recharge.

Warnings

Tools required

Parts

• AC Low Pressure Switch × 1 — Use OEM specification
• AC line O-rings × 2 — Ensure R-1234yf compatibility
• PAG oil for AC system × 1 — R-1234yf compatible PAG oil

Preparation

1. Park vehicle on level surface and engage parking brake
2. Ensure ignition is off and key fob is at least 15 feet away from vehicle
3. Connect 12V battery maintainer to prevent low voltage faults during service
4. Allow AC system to equalize for at least 5 minutes if recently operated
5. Verify AC refrigerant recovery machine is certified for R-1234yf service
6. Locate AC low pressure switch on the accumulator/receiver-drier assembly on the passenger side of the engine compartment

Procedure

1. 1

   Recover refrigerant from AC system
   Connect the AC recovery machine to the high and low pressure service ports. Follow machine manufacturer procedures to fully recover all R-1234yf refrigerant from the system. Record the amount recovered for recharge purposes. Verify system shows 0 psi on both high and low side gauges before proceeding.
2. 2

   Disconnect electrical connector
   Locate the electrical connector on the AC low pressure switch mounted to the accumulator. Press the locking tab and disconnect the electrical harness connector from the switch. Move the harness aside to provide clearance.
3. 3

   Remove AC low pressure switch
   Using the appropriate wrench, carefully unthread the AC low pressure switch from the accumulator port. The switch threads directly into the accumulator housing. Once threads are clear, remove the switch completely and immediately inspect the O-ring seal. Discard the old switch and O-ring.
4. 4

   Prepare accumulator port and new switch
   Inspect the threads in the accumulator port for damage or debris. Clean threads if necessary. Install a new R-1234yf compatible O-ring onto the new AC low pressure switch. Lightly coat the O-ring with R-1234yf compatible PAG oil to ensure proper sealing and ease installation.
5. 5

   Install new AC low pressure switch
   Thread the new AC low pressure switch into the accumulator port by hand until finger-tight. Ensure the switch threads smoothly without cross-threading. Once seated, use a torque wrench to tighten the switch to the manufacturer's specification for AC line fittings.
   Torque spec

   AC Line Fittings20 Nm (15 lb-ft)
6. 6

   Reconnect electrical connector
   Reconnect the electrical harness connector to the new AC low pressure switch. Ensure the connector locks securely with an audible click. Gently tug on the connector to verify proper engagement.
7. 7

   Evacuate AC system
   Connect the AC service machine to both high and low pressure service ports. Evacuate the system to a deep vacuum (minimum 29 inches Hg) for at least 30 minutes. This removes all air and moisture from the system. Monitor for vacuum decay to verify system integrity before recharging.
8. 8

   Recharge AC system
   Using the AC service machine, recharge the system with the previously recovered amount of R-1234yf refrigerant, plus 1-2 oz to account for system losses. Verify the total charge matches the underhood AC specification label (typically 1.54 lbs / 700 grams for this vehicle). Add PAG oil if required by service machine calculations.

Reassembly

1. Verify all electrical connections are secure and locked
2. Ensure no tools or parts were left in the engine compartment
3. Remove battery maintainer if used

Verification

• Start the vehicle and turn AC to maximum cooling with recirculation mode on
• Allow system to run for 5 minutes and verify compressor cycles on and off normally
• Check AC low pressure reading on service machine (should be 25-45 psi at idle with ambient temperature 70-80°F)
• Verify AC high pressure reading is appropriate for ambient temperature (150-250 psi typical)
• Inspect the new switch connection point for any signs of refrigerant leakage using electronic leak detector
• Verify cold air output from dashboard vents (typically 38-42°F at full cold setting)
• Use scan tool to verify no AC system fault codes are present
• Confirm AC low pressure switch signal is present in vehicle data stream when AC is commanded on

Related trouble codes on this vehicle

Codes that commonly send this job to the bay — tap one for symptoms, causes, and diagnostic steps.

Chasing one of these codes and not sure which part is guilty? Ask a master mechanic about YOUR car →

More procedures for this vehicle