B1968 – A/C Water Pump Detection Circuit Failure

The ODBII code B1968 indicates a failure in the A/C water pump detection circuit, suggesting that the vehicle’s system is unable to properly monitor or communicate with the A/C water pump.

The severity of ODBII code B1968 A/C Water Pump Detection Circuit Failure is generally considered moderate.

Common Causes For: B1967 A/C Post Heater Sensor Circuit Short To Ground

• Faulty A/C water pump
• Wiring issues (shorts, opens, or corrosion)
• Bad connectors or terminals
• Failed A/C control module
• Blown fuse
• Software issues in the vehicle’s control module
• Grounding problems

Common misdiagnosis for B1968 A/C Water Pump Detection Circuit Failure

• Faulty A/C compressor
• Refrigerant leak
• Electrical issues in the A/C system
• Bad A/C control module
• Wiring harness problems
• Faulty temperature sensors
• Incorrect A/C system pressure readings
• Malfunctioning engine cooling system components

Common Troubleshooting Steps

The OBD-II code B1968 refers to a failure in the A/C water pump detection circuit. This code is typically associated with vehicles that have an electric water pump for the air conditioning system. Here are some common troubleshooting steps to diagnose and resolve the issue:

• Check the Vehicle’s Battery and Charging System: Ensure the battery is fully charged and in good condition.
• Check the alternator output to ensure it is providing adequate voltage.
• Inspect the A/C Water Pump: Locate the A/C water pump and visually inspect it for any signs of damage or wear.
• Ensure that the pump is securely mounted and that there are no leaks.
• Test the A/C Water Pump Operation: If possible, manually activate the A/C water pump to see if it operates correctly.
• Listen for unusual noises that may indicate a mechanical failure.
• Check Electrical Connections: Inspect the wiring and connectors leading to the A/C water pump for any signs of corrosion, damage, or loose connections.
• Ensure that all connectors are securely attached.
• Test the A/C Water Pump Circuit: Use a multimeter to check for voltage at the pump connector when the A/C is activated.
• Check for continuity in the wiring harness leading to the pump.
• Inspect Fuses and Relays: Check the vehicle’s fuse box for any blown fuses related to the A/C system or water pump.
• Test any relays associated with the A/C water pump to ensure they are functioning properly.
• Scan for Additional Codes: Use an OBD-II scanner to check for any other related trouble codes that may provide more context to the issue.
• Address any additional codes that may be present.
• Check the A/C Control Module: If the pump and circuit appear to be functioning correctly, the issue may lie within the A/C control module.
• Inspect the module for any signs of damage or failure.
• Consult Technical Service Bulletins (TSBs): Check for any manufacturer-specific TSBs related to the B1968 code or A/C water pump issues for your vehicle make and model.
• Clear Codes and Test Drive: After performing repairs or inspections, clear the trouble codes and take the vehicle for a test drive to see if the code returns.1
• Seek Professional Help: If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or technician for further diagnosis. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the B1968 OBD-II code.