B1968 — A/C Water Pump Detection Circuit Failure #

Note: The code description may differ between manufacturers. Always refer to your OEM (Original Equipment Manufacturer) documentation for precise wording.

• Ford: A/C Water Pump Detection Circuit Failure
• Lincoln: A/C Water Pump Detection Circuit Malfunction
• Mercury: A/C Water Pump Circuit Error

Overview of DTC B1968 #

The B1968 diagnostic trouble code (DTC) indicates a detected failure within the air conditioning (A/C) water pump detection circuit. This circuit is responsible for monitoring the operation and status of the auxiliary water pump, a component that helps circulate coolant through the A/C system to aid in temperature regulation. When the vehicle’s control module, often called the Body Control Module (BCM), senses an irregularity—such as an open circuit, short, or unexpected voltage—it triggers this code. A properly functioning detection circuit is essential for efficient cooling and to prevent potential damage to the A/C components. Ignoring this code may lead to reduced cabin comfort and, in rare cases, overheating of A/C system parts.

Common Symptoms for Code B1968 #

When B1968 is stored, you may notice several warning signs—although sometimes, symptoms can be subtle or intermittent. Most often, changes in the A/C system’s performance are the first clues. If you’re experiencing any of the following, the detection circuit failure could be the culprit:

• Reduced air conditioning cooling performance
• Fluctuating or inconsistent cabin temperature
• Unusual noises from the A/C system area
• Warning lights or error messages on the dashboard
• Intermittent or non-functioning A/C water pump

Probable Causes for B1968 (Most to Least Common) #

Like a detective tracing clues, pinpointing the root cause of B1968 involves understanding the circuit’s vulnerabilities. The most common culprits are related to electrical or component failures within the detection system:

1. Faulty or failing A/C water pump
2. Damaged, corroded, or loose wiring/connectors in the detection circuit
3. Blown fuse or relay associated with the A/C water pump circuit
4. Malfunctioning detection sensor within the A/C system
5. Faulty Body Control Module (BCM) or related control module
6. Corrosion or water ingress in the wiring harness

Step-By-Step Diagnostic Procedure for B1968 #

Diagnosing B1968 is a systematic process—think of it as following a treasure map where each step brings you closer to the solution. Here’s how a professional or capable DIYer should approach it:

• 1. Confirm the code with a professional-grade OBD-II/EOBD scanner and check for any related codes.
• 2. Visually inspect the A/C water pump and its electrical connectors for obvious signs of damage, loose connections, or corrosion.
• 3. Test the A/C water pump operation by applying direct battery voltage (following OEM safety procedures) to see if the pump runs.
• 4. Use a multimeter to check for continuity and correct voltage in the detection circuit wiring.
• 5. Check the fuse and relay related to the A/C water pump circuit; replace if blown or faulty.
• 6. Inspect the detection sensor and, if possible, test its output with an oscilloscope or as per OEM guidelines.
• 7. If all hardware checks out, consider a possible fault in the BCM or control module. Consult OEM diagnostics for further module testing or reprogramming.

Possible Repairs for B1968 #

Repairing the B1968 code depends on the underlying cause found during diagnosis. Each correction should address the specific failure, and it’s wise to clear the code and test the system after each repair step:

• Replace the A/C water pump if found defective
• Repair or replace damaged, corroded, or loose wiring/connectors in the detection circuit
• Replace blown fuse or faulty relay in the A/C water pump circuit
• Replace or recalibrate the detection sensor as required by OEM procedures
• Repair or replace the Body Control Module if diagnosed as faulty
• Seal and protect wiring harnesses to prevent future corrosion or water ingress

Is It Safe to Drive with Code B1968? #

Generally, driving with code B1968 is possible but not recommended for extended periods. While the vehicle may remain operational, you risk reduced A/C cooling efficiency and possible long-term damage to system components if the water pump isn’t functioning. In severe cases, overheating of A/C system parts could occur, so it’s best to address this code promptly to maintain comfort and avoid further issues.

Vehicles Most Commonly Affected by B1968 #

The B1968 code is most frequently reported in specific Ford, Lincoln, and Mercury vehicles, particularly those equipped with advanced climate control systems and auxiliary water pumps:

• Ford Fusion (select model years)
• Ford Taurus
• Lincoln MKZ
• Ford Edge
• Mercury Milan

Always check OEM bulletins, as other makes and models may be affected depending on their specific HVAC system configuration.

Common Mistakes & Best Practices for B1968 #

Misdiagnosis with B1968 often stems from overlooking basic electrical checks or replacing parts prematurely. To avoid unnecessary repairs and costs, keep these points in mind:

• Don’t replace the A/C water pump without confirming power and ground at the connector
• Always check and repair wiring/connectors before suspecting control modules
• Use OEM wiring diagrams to trace the detection circuit accurately
• Clear codes and retest after each repair to ensure the issue is resolved
• Document all findings and repairs for future reference

Quick FAQ for B1968 #

Still have questions? Here are some rapid answers to the most common concerns:

• Q: Will clearing the code fix my A/C problem?
  A: No—simply clearing the code won’t resolve the root cause. Proper diagnosis and repair are necessary.
• Q: Can a weak battery cause B1968?
  A: Rarely. While low voltage can trigger some electrical codes, B1968 is usually due to circuit or component issues specific to the A/C water pump.