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P1237 Diagnostic Code in 2000 Ford Taurus Flex Fuel: What It Means and How to Fix It

Model: Ford Taurus Fault Code: P1237 Posted: 2007-08-31 14:32

I recently encountered a P1237 diagnostic code on my 2000 Ford Taurus with flex fuel capability. The vehicle runs smoothly, idles steadily, and cranks easily after refueling. I noticed the code appear only after filling up the tank. Despite no noticeable performance issues, I'm concerned about what this error means. According to technical references, P1237 indicates a 'Fuel Pump Secondary Circuit Fault.' However, I can't find detailed guidance on how to diagnose or resolve it independently. Since my car is running fine, I'm wondering if the code might be inaccurate or intermittent. Any insights into the actual cause—especially related to the secondary fuel pump circuit—would be greatly appreciated.

Related fault codes

P1237

Comments (3)

Anonymous 2007-08-31 14:35

It's best to have a professional scan the vehicle using an OBD2 scanner to confirm the exact definition of the P123 or P1237 code. While the code suggests a secondary fuel pump circuit fault, if the fuel pump is functioning normally and the car runs well, the reading might be inaccurate or intermittent.

Anonymous 2007-09-04 07:52

The Powertrain Control Module (PCM) typically monitors resistance in the secondary fuel pump circuit. A possible issue could be intermittent connectivity—especially between the relay switch and the fuel pump itself. In Ford vehicles, inertia switches are common culprits, often causing high resistance or even melting due to overheating. Check for signs of discoloration, burning, or physical damage on the switch. Your owner's manual should list the exact location. For complex diagnostics, it’s recommended to consult a certified mechanic or dealership.

Anonymous 2012-02-08 22:36

How do I locate the fuel pump secondary circuit or the relay switch in my 2000 Ford Taurus? Can you provide specific steps or reference points from the owner's manual?