So while driving to work I start experiencing some weird behavior with the transmission. It would shift hard and seem like it wasn't pulling hard at all. I looked down and saw the overdrive off light flashing. Got to work, turned the car off then started back up and the light was off. Any thoughts?

 

You'll need to go someplace that can scan for transmission codes, the blinking light says you have one. The average parts store scanner won't do.

 

I think that is one of the speed sensors...there are 3 of them - research VSS, TSS and hard shifts and you'll find a bunch of threads about it.

 

So a OBD2 reader wont tell me what faults are in?

 

I believe it will. The OD light flashing is an indication of a code - that's why I referenced the speed sensors above. That light only flashes for one thing.

 

So no codes for sensors, but there were 2 codes, P0683: Glow plug control module to powertrain P0676: Cylinder 6 plug circuit.

 

That means you have a diesel, and that means an "ordinary" scanner won't work on your rig. I'm not saying that's what you used, but you need to make sure the scanner can read transmission codes, or pay a shop to scan your Ex.

Without the trans code, there's absolutely no way anyone can narrow down what your problem is. We can all guess until the cows come home and that's all they'd be, guesses.

Stewart

 

Not sure if I read that correctly, but just FYI, there are hundreds of different transmission codes that can cause the OD light to flash.

Stewart

 

So basically take it to my Ford dealership and have them scan it? It was a regular OBD2 reader that I used at autozone.

 

Wow, i'm surprised it gave you the code for the GPCM. I wonder what kind of reader it was. Most of the standard OBD 2 readers at places like Autozone can't read the 7.3L PSD because the 7.3's aren't OBD 2 compliant.

Stewart

 

I gave it a try because I don't want to pay Ford $100 just to connect a freaking reader, but I may have them do it when I take it back in to fix the leaking fitting on my transmission coolant line.

 

I'd like to see your list with just 100. What's the point of this forum if all you can provide is that there are 100's of codes? Heck, I'd even be surprised if you could come up with a list of the top 5 reasons that OD light blinks. Perhaps, if a poster could get a list of differentials, he could start checking them off until he found the answer to his problem. Then, he could add his problem and solution to the database. Instead, it's "yep, you have an issue, go to the dealer." I think that sort of help would be much more valuable than random conjecture and posts of how to install broken mudflaps...

If these trucks and motors and transmissions are some darn reliable then why assume the problem is 1 of hundreds instead of something a member has already discovered to be "common." I've found no such list of common issues yet.

 

A good independent shop can read them, too. Autozone CANNOT read transmission codes.

OK, here's a list of what can flash the OD OFF light.

P0700 Transmission Control System (MIL Request)
P0703 Brake Switch B Input Circuit
P0704 Clutch Switch Input Circuit
P0705 Transmission Range Sensor Circuit (PRNDL Input) *
P0707 Transmission Range Sensor Circuit Low Input *
P0708 Transmission Range Sensor Circuit High Input *
P0712 Transmission Fluid Temperature Sensor Circuit Low Input ^
P0713 Transmission Fluid Temperature Sensor Circuit High Input ^
P0715 Turbine Shaft Speed Sensor Circuit *
P0717 Turbine Shaft Speed Sensor Circuit No Signal
P0718 Turbine Shaft Speed Sensor Circuit Intermittent ^
P0720 Output Shaft Speed Sensor Circuit *
P0721 Output Shaft Speed Sensor Circuit Range/Performance ^
P0722 Output Shaft Speed Sensor Circuit No Signal
P0723 Output Shaft Speed Sensor Circuit Intermittent
P0731 Gear 1 Incorrect Ratio ^
P0732 Gear 2 Incorrect Ratio ^
P0733 Gear 3 Incorrect Ratio ^
P0734 Gear 4 Incorrect Ratio ^
P0735 Gear 5 Incorrect Ratio ^
P0741 Torque Converter Clutch Solenoid Circuit Performance Or Stuck Off ^
P0743 Torque Converter Clutch Solenoid Circuit Electrical *
P0745 Pressure Control Solenoid A *
P0746 Pressure Control Solenoid A Performance or Stuck Off *
P0750 Shift Solenoid A *
P0751 Shift Solenoid A Performance or Stuck Off *
P0755 Shift Solenoid B *
P0756 Shift Solenoid B Performance or Stuck Off *
P0760 Shift Solenoid C *
P0761 Shift Solenoid C Performance or Stuck Off *
P0765 Shift Solenoid D *
P0766 Shift Solenoid D Performance or Stuck Off *
P0770 Shift Solenoid E *
P0771 Shift Solenoid E Performance or Stuck Off *
P0775 Pressure Control Solenoid B *
P0779 Pressure Control Solenoid B Intermittent
P0781 1-2 Shift ^
P0782 2-3 Shift ^
P0783 3-4 Shift ^
P0791 Intermediate Shaft Speed Sensor Circuit
P0794 Intermediate Shaft Speed Sensor Circuit Intermittent ^
P0795 Pressure Control Solenoid C *
P0796 Pressure Control Solenoid C Performance or Stuck Off *
P0797 Pressure Control Solenoid C Stuck On *
P0799 Pressure Control Solenoid C Intermittent
P0812 Reverse Input Circuit
P0814 Transmission Range Display Circuit
P0815 Upshift Switch Circuit
P0816 Downshift Switch Circuit
P0818 Driveline Disconnect Switch Input Circuit
P0840 Transmission Fluid Pressure Sensor/Switch A Circuit
P0844 Transmission Fluid Pressure Sensor/Switch A Circuit Intermittent
P1700 Transmission Indeterminate Failure (Failed to Neutral)
P1701 Reverse Engagement Error
P1702 Transmission Range Sensor Circuit Intermittent
P1703 Brake Switch Out Of Self Test Range
P1704 Transmission Range Circuit Not Indicating Park/Neutral During Self Test
P1705 Transmission Range Circuit Not Indicating Park/Neutral During Self Test
P1709 Park Neutral Position Switch Out Of Self Test Range
P1711 Transmission Fluid Temperature Sensor Out Of Self Test Range
P1712 Transmission Torque Reduction Request Signal
P1713 Transmission Fluid Temperature Sensor In Range Failure (< 50 deg F) ^
P1714 Shift Solenoid A Inductive Signature *
P1715 Shift Solenoid B Inductive Signature *
P1716 Shift Solenoid C Inductive Signature *
P1717 Shift Solenoid D Inductive Signature *
P1718 Transmission Fluid Temperature Sensor In Range Failure (> 250 deg F)
P1727 Coast Clutch Solenoid Inductive Signature
P1728 Transmission Slip
P1729 4x4L Switch
P1731 1-2 Shift Malfunction
P1732 2-3 Shift Malfunction
P1733 3-4 Shift Malfunction
P1740 Torque Converter Clutch Solenoid Inductive Signature *
P1741 Torque Converter Clutch Solenoid Control Error
P1742 Torque Converter Clutch Solenoid Circuit Failed On *
P1743 Torque Converter Clutch Solenoid Circuit Failed On ^
P1744 Torque Converter Clutch Solenoid Circuit Performance *
P1746 Pressure Control Solenoid A Open Circuit ^
P1747 Pressure Control Solenoid A Short Circuit *
P1749 Pressure Control Solenoid A Failed Low
P1751 Shift Solenoid A Performance ^
P1754 Coast Clutch Solenoid Circuit ^
P1756 Shift Solenoid B Performance ^
P1760 Pressure Control Solenoid A Short Circuit Intermittent ^
P1761 Shift Solenoid C Performance ^
P1762 Overdrive Band Failed Off *
P1766 Shift Solenoid D Performance ^
P1767 Torque Converter Clutch Circuit ^
P1768 Performance/Normal/Winter Mode Input
P1770 Clutch Solenoid Circuit
P1780 Transmission Control Switch (O/D Cancel) Circuit Out Of Self Test Range
P1781 4X4L Circuit Out Of Self Test Range
P1782 Performance/Economy Switch Circuit Out Of Self Test Range
P1783 Transmission Overtemperature Condition ^
P1784 Transmission Mechanical Failure - First And Reverse
P1785 Transmission Mechanical Failure - First And Second
P1786 3-2 Downshift Error
P1787 2-1 Downshift Error
P1788 Pressure Control Solenoid B Open Circuit *
P1789 Pressure Control Solenoid B Short Circuit *
P1795 Inconsistent CAN Level *
P1804 4-Wheel Drive High Indicator Circuit Open or Shorted To Ground
P1806 4-Wheel Drive High Indicator Short To Battery
P1808 4-Wheel Drive Low Indicator Circuit Open or Short To Ground
P1810 4-Wheel Drive Low Indicator Short To Battery
P1812 4-Wheel Drive Mode Select Switch Circuit Open
P1815 4-Wheel Drive Mode Select Switch Circuit Short To Ground
P1819 Neutral Safety Switch Input Short To Ground
P1820 Transfer Case LO To HI Shift Relay Circuit Open Or Short To Ground
P1822 Transfer Case LO To HI Shift Relay Coil Short To Battery
P1824 4-Wheel Drive Electric Clutch Relay Open Or Short To Ground
P1826 4-Wheel Drive Electric Clutch Relay Short To Battery
P1828 Transfer Case HI To LO Shift Relay Coil Circuit Open Or Short To Ground
P1830 Transfer Case HI To LO Shift Relay Coil Circuit Short To Battery
P1832 Transfer Case 4-Wheel Drive Solenoid Circuit Open or Short To Ground
P1834 Transfer Case 4-Wheel Drive Solenoid Circuit Short To Battery
P1838 No Shift Motor Movement Detected
P1846 Transfer Case Contact Plate 'A' Circuit Open
P1850 Transfer Case Contact Plate 'B' Circuit Open
P1854 Transfer Case Contact Plate 'C' Circuit Open
P1858 Transfer Case Contact Plate 'D' Circuit Open
P1866 Transfer Case Cannot Be Shifted
P1867 Transfer Case Contact Plate General Circuit Failure
P1876 Transfer Case 2-Wheel Drive Solenoid Circuit Open Or Short To Ground
P1877 Transfer Case 2-Wheel Drive Solenoid Circuit Short To Battery

So which one of those do YOU think caused the problem? I don't know, maybe I don't know enough about transmissions. You seem to be an expert, please teach me.

The way I learned to diagnose transmission problems is to get the codes first. That's the least expensive way to fix what's wrong. The computer can tell you what it's seeing is wrong, why wouldn't you use that information? Those that want a diagnosis without the information just don't know enough about this to be helpful.

And you won't find a list like that from me. It just leads to wrong diagnosis and people wasting money replacing good parts.

 

Really? Now was that really called for?

I certainly hope Mark K stumbles into this thread.

 

I was wrong.