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2001 Ford Ranger P1780 Transmission Code: Causes, Symptoms & Fixes for Vibration and Engine Miss

Model: 2001 Ford Ranger Fault Code: P1780 Posted: 2014-06-30 09:47

I own a 2001 Ford Ranger with a 3.0L LV6 engine (4x2 configuration) that is experiencing significant vibration and engine misfiring. The OBD2 scanner has detected a P1780 code: 'Transmission Control Switch Out of Safe Test Range'. I'm wondering if this transmission issue could be directly causing the shaking and engine miss symptoms. The truck has 168,548 miles on it. I've already replaced all front-end components except the stabilizer bar, including spark plugs, wires, tires, and shocks. Despite these efforts, the problems persist. What other diagnostics or repairs should I consider? Thank you for your guidance. Larry Kennedy

Related fault codes

P1780

Comments (3)

Anonymous 2014-06-30 10:55

This issue may stem from three key areas: - Shimmy/vibration: Likely related to suspension, alignment, or wheel balance. Please specify at what speed the vibration occurs. - Engine misfire: Perform basic diagnostics—check spark presence at all plugs, vacuum lines, and fuel pressure. Confirm compression readings. - Is there a spark at every plug? If not, that’s a primary concern. - Transmission issue: The P1780 code often points to the Overdrive (OD) Torque Converter Clutch (TCC) control switch—this is frequently faulty. Check if the OD light is on or flashing when driving.

Anonymous 2014-06-30 13:12

The vibration occurs at all speeds. The truck has been aligned six times within three years, with each alignment performed by different shops. All spark plugs have been replaced and are currently firing properly—installed last month. The OD light has occasionally come on over the past six months. Thank you for your help again. Larry Kennedy

Anonymous 2014-06-30 13:54

The suspension has already been inspected: tierods, ball joints, bushings, and front-to-rear control arm alignment have all been checked. All tires are new, properly balanced, and the same size. Could there be an issue with the driveshaft being out of phase? Is it possible a wheel is bent—especially since I only addressed front-end components? For engine misfire: Even if spark is present, fuel delivery or injector performance could still be at fault. Are all plugs showing similar color and condition? Try using a dedicated SEAFOAM injector cleaner as a temporary fix and report back. Note: The P1780 code frequently relates to the OD TCC switch located at the end of the transmission shifter arm—check for broken wiring or loose connections. A Google search for 'Ford OD switch' can provide more detailed troubleshooting steps.