Blinking O/D OFF light. How to diagnose with no codes

[Patrick Lao]

Hello,

I just purchased a 2002 FORD Explorer XLT 4.0 V6 and I think with the 5R55W tranny. They said that this is the 3rd tranny. The OG was replaced, then the replacement was replaced. My question is that the O/D OFF light is blinking but there is no CEL. I hear there should be a code but there is no codes.

I put a code reader on it myself and then had it smog checked and passed.

How can I diagnose the blinking light so that I can start to prevent transmission failure? Is there a special code reader for that light/transmission codes?

There is no problems with shifting or getting into any gear.

 

[Drewmcg]

That blinking O/D error is most often associated with failing overdrive servos on this truck. But presumably other errors are associated with it as well. You can try a different scan tool (maybe take it to a few different auto parts stores or shops with different scanners). It is possible that there is some no-scanner-required number of blinks correlation to a particular fault, but I don't know this.

If you are in an early overdrive band slipping phase, you may be able to detect it early (i.e., before burning out the band) by cruising along in "D" at 35-45 mph or so with light throttle, possibly on a slight uphill, and seeing if the overdrive engages normally, or slips.

 

[Patrick Lao]

That blinking O/D error is most often associated with failing overdrive servos on this truck. But presumably other errors are associated with it as well. You can try a different scan tool (maybe take it to a few different auto parts stores or shops with different scanners). It is possible that there is some no-scanner-required number of blinks correlation to a particular fault, but I don't know this.

If you are in an early overdrive band slipping phase, you may be able to detect it early (i.e., before burning out the band) by cruising along in "D" at 35-45 mph or so with light throttle, possibly on a slight uphill, and seeing if the overdrive engages normally, or slips.

Ok thanks for the info, especially the tip to test the overdrive band.

 

[Mbrooks420]

Like mentioned above you need a different scanner. If it’s blinking there are stored codes.

 

[Patrick Lao]

Like mentioned above you need a different scanner. If it’s blinking there are stored codes.

It was scanned with a decent scanner, about a $150 scanner. Are we just talking about normal OBD2 scanners that read trouble codes?

 

[Mbrooks420]

It needs to be able to read stored transmission codes. Most generic OBDII scanners don’t, just like most don’t read ABS faults.

 

[Mbrooks420]

Most transmission shops will diagnose issues free. I’d take it back to wherever rebuilt it last.

 

[Patrick Lao]

Most transmission shops will diagnose issues free. I’d take it back to wherever rebuilt it last.

Oh okay. Thanks. I'll start looking for one in my area.

 

[Patrick Lao]

It needs to be able to read stored transmission codes. Most generic OBDII scanners don’t, just like most don’t read ABS faults.

Ok. Thanks. I will try to see if a transmission place will read them, otherwise I will look into buying/borrowing one.

 

[Mbrooks420]

I believe FORscan will

 

[donalds]

Reading this makes me love my elm adaptor and forscan. You may want to invest

 

[donalds]

I believe FORscan will

We were thinking the same

 

[donalds]

https://www.amazon.com/VDIAGTOOL-ELM327-Interface-Diagnostic-Scanner/dp/B071GQ8PRD


Download FORScan

 

[Patrick Lao]

If you are in an early overdrive band slipping phase, you may be able to detect it early (i.e., before burning out the band) by cruising along in "D" at 35-45 mph or so with light throttle, possibly on a slight uphill, and seeing if the overdrive engages normally, or slips.

I just re-read this and had thoughts: My OD is working just fine and not slipping. I was testing it when I first saw the light a day ago and pressing the OD button while driving and noticing that the RPMs are higher when OFF and lower when ON. Everything shifts just fine, so if the O/D OFF light is not an indication of failed OD bands, what is the next possible failure?

 

[donalds]

That od light is the transmissions check engine light

It could be one of a hundred things get the codes

 

[Mbrooks420]

It could be anything related to the transmission. It’s like trying to figure out a CEL without the code.

 

[Patrick Lao]

That od light is the transmissions check engine light

It could be one of a hundred things get the codes

Thanks. I"ll get them.

 

[GERM37]

Hello,

I just purchased a 2002 FORD Explorer XLT 4.0 V6 and I think with the 5R55W tranny. They said that this is the 3rd tranny. The OG was replaced, then the replacement was replaced. My question is that the O/D OFF light is blinking but there is no CEL. I hear there should be a code but there is no codes.

I put a code reader on it myself and then had it smog checked and passed.

How can I diagnose the blinking light so that I can start to prevent transmission failure? Is there a special code reader for that light/transmission codes?

There is no problems with shifting or getting into any gear.

HI,
I have 2003 explorer sport trac and had the same problem I was lucky it came with a 3000 mile or 3 month warranty and they fixed it, they replaced the the whole valve body and the inside trans. wiring harness and so far no more problems.
GOOD LUCK.
SHERMAN

 

[imp]

I just re-read this and had thoughts: My OD is working just fine and not slipping. I was testing it when I first saw the light a day ago and pressing the OD button while driving and noticing that the RPMs are higher when OFF and lower when ON. Everything shifts just fine, so if the O/D OFF light is not an indication of failed OD bands, what is the next possible failure?

@Patrick Lao
When my O/D OFF light started flashing, the code was for a failed Torque Converter Clutch Solenoid. I found that I could detect that myself, so can you. Take the vehicle up to cruising speed under easy throttle on open flat road, at around 55 mph if you LIGHTLY increase gas pedal pressure and the engine speed as noted on the tachometer immediately increases, the TCC is not engaged as it should be. If the clutch is engaged, engine speed will not jump higher, as the torque converter is locked out of the game.

This particular solenoid of all 8 of them gets the biggest workout, as while driving at speed, each release of the gas pedal for whatever reason turns the TCC solenoid off, disengages the TCC, then upon resuming throttle it must turn on and engage again. If one drives with a foot-on, foot-off the gas pedal, he is slowly killing that solenoid. I replaced mine, the TCC resumed working properly, and the flashing light was gone.

BTW, if you buy a code reader, it must specifically say "CAN Protocol" capable, or it will not read transmission or chassis or ABS codes. imp

 

[Patrick Lao]

This particular solenoid of all 8 of them gets the biggest workout, as while driving at speed, each release of the gas pedal for whatever reason turns the TCC solenoid off, disengages the TCC, then upon resuming throttle it must turn on and engage again. If one drives with a foot-on, foot-off the gas pedal, he is slowly killing that solenoid. I replaced mine, the TCC resumed working properly, and the flashing light was gone.

This is good to know.

BTW, if you buy a code reader, it must specifically say "CAN Protocol" capable, or it will not read transmission or chassis or ABS codes. imp

Perfect.

Take the vehicle up to cruising speed under easy throttle on open flat road, at around 55 mph if you LIGHTLY increase gas pedal pressure and the engine speed as noted on the tachometer immediately increases, the TCC is not engaged as it should be. If the clutch is engaged, engine speed will not jump higher, as the torque converter is locked out of the game.

I'll be testing this asap. I have some highway driving each day. Thanks for all the info!