[bobstrater]

Hello. Started my car yesterday after it sat for 3 days and the "O/D Off" light stayed lit. I drove it a few miles at low speeds (30 to 40mph) and I was unable to turn the overdrive on with the switch. I then needed to get onto the highway to get home, and it still wouldnt come on. I drove a distance at 50mph and kept flipping into neutral down hills so I wouldnt blow my engine.

I then got pulled over by a state trooper for my odd driving.

After the trooper left, I drove away and the overdrive had turned itself on.

Over the next few miles it automaticaly turned on and off on its own.

Any ideas?
Thanks

 

[elsolo]

The wire to that switch is probably grounding out intermittently.

 

[bobstrater]

Any idea where the wire would head to?

 

[Marde]

After the switch, it goes to the PCM connector C415 Pin 29.


One way to test elsolo's theory is to disable the switches ability to engage OD OFF. Here is one way you can do this:

Buried underneath the gear selector is a connector C931 and Pin 5 has a Green wire with a Black stripe. Cut that wire and cap it with some electrical tape. That wire is ALWAYS HOT (12Vdc) when the car is On. Place your cut in a spot that allows you to go back and repair/splice it. Test drive your car. If OD still goes OFF, the wiring and/or the switch is not causing the problem... well... unless the wire (going to the PCM) is damaged and touching onto some other source of 12V. So, here is a different idea; you could do similar at the PCM. The wire at Pin 29 is also colored the same, Grn/Blk. Once the wire is cut, this would allow you to connect a DVM (at the PCM) and monitor the signal that is coming from the OD On/Off switch. Signal High = OD Off: Signal Low = OD On. Once the meter is setup, you could do this while driving.

Not sure, but that switch/signal might be a "momentary" type.

Info above is based on 2002/2003 Focus Diagram 307-01-00.

 

[Marde]

I drove a distance at 50mph and kept flipping into neutral down hills so I wouldnt blow my engine.

BTW I often drive with OD Off (in 3rd gear) and hold it at 50 mph and the RPM's are not too high at all. With OD on and light throttle, my car grabs 4th gear at about 42 - 44 mph.

The wiring test above is a decent idea and test, but my guesses are leaning more towards a defective trans solenoid or related other. Cross fingers that disabling the OD On/Off wiring works out for you.

Have you ever done a trans fluid flush or replace? Is the fluid level set right?

 

[amc49]

OD off is virtually the same as an old school car in the '70s, no blowing the engine going to happen there, it can do that for years.

The switch is momentary, it signals the PCM to do a flipflop.