Originally posted by HITMANinMI:

Some folks on here will tell you, you can only get the codes when the light is flashing, they are incorrect.





I will post this for you "one more time"!

From the `98 Ford Service CD -
"The MIL is illuminated for all emissions related electrical component malfunctions. For malfunctions attributable to a mechanical component (such as a clutch, gear, band, valve, etc.), some transmissions are capable of not commanding the mechanically failed component and providing the remaining maximum functionality (functionality is reassessed on each power up)- in such case a non-MIL Diagnostic Trouble Code (DTC) will be stored and, if so equipped, a Transmission Control Indicator Light (TCIL) will flash."

What this basically means, is that the CEL will illuminate, and stay that way, during an emmissions related electrical component faliure or malfunction. That is until the PCM memory is either cleared manually or the fault is not detected after two consecutive drive cycles.

If there is a mechanical failure, in the tranny, it will cause the TCIL (O/D light) to flash, which means that the PCM has stored a code indicating which fault it was. But!! This code will be cleared once the engine is turned off.

So. If your O/D light flashed, there was a code there to be read. If you turned your engine off before you could actually read that code, that code would disappear. If when you started your car again and the CEL was not on or the O/D light did not flash, there is nothing there to read. You will have to wait until the fault happens again.

I will even try to simlify it for you even further...

When your "Check Engine Light" (CEL) illuminates, there will be a code stored in the computer that can only be cleared by disconnecting power to the PCM or using a coder reader or scanner capiable of clearing out the fault codes through commands since directly to the PCM. Under these conditions, you can also read these codes, at anytime, until they are cleared by either method above.

The O/D light does not work the same way. I explained it above, so if you still don't get it... read it again!

Last edited by unisys12; 08/09/04 05:49 PM.
Phillip Jackson `98 Mystique LS 262K+ and counting... ATX rebuilt @ 151K "This storm has broken me, my only friend!" RIP Dime