Hey Guys,
I recently bought a 92 F150 AOD. The PO told me it hard shifted before I purchased it but for the price and the purpose I wanted for the truck it was hard to pass up. I found several posts on the hard shift like checking the tranny fluid level and TV cable adjustment and will try those remedies, When I ran the codes i came up with 3...I tried to find each of them, but the piecemealing was making me nuts and the repair manuals just don't give enough information! So if someone wouldnt mind helping me out with my list...

637 TOT circuit above max range. I found something about this. One post said the transmission is shifting too fast and causes the transmission to over heat. Is that what this code means and what do i do about it and could this be causing the hard shift too?

334 EGR closed voltage higher than expected. Couldnt find anything on this.

624 EPC solenoid or driver circuit failure. Again, couldnt find anything on this.

Any help will be greatly appreciated!!

Thanks, Greg

 

Does your truck have an OD off switch on the shift lever? If so you have the E4OD, if not you probably have the 4R70W(AODE).

Both 637 and 624 are transmission codes, the shift solenoid problem is likely the cause of the hard shifting and Tranny oil Temp(TOT) code, I suggest you replace this solenoid.

Code 334 is for the EGR, it's probably a good idea to remove the valve and clean it and then ceck that it fully opens and closes. Then attach it to the engine and measure the closed voltage to see if it is within spec, and if not replace it. See www.fordfuelinjection.com for details on the engine sensors.

 

If you are getting a 624 code you do not have the TV cable adjustment or a AOD transmission. Maybe an E4OD?
An AOD would have two number codes and not three and you would not have an EPC code.

You did not say if the codes are KOEO or CM so I will guess KOEO.

Service Code 637 indicate that the TOT sensor output is greater than Self-Test maximum value of 4.8 volts.

Possible causes:
-- Damaged TOT sensor.
-- Open harness circuit(s).
-- Damaged processor.

Service Code 334 in Key On Engine Off or Engine Running Self-Test indicates that the EGR valve and/or EGR Valve Position (EVP) sensor may not be fully seated in the closed position. The EVP sensor voltage is greater than the closed limit voltage of 0.67 volts. Because of the preload on the installed EVP sensor, it is very difficult to determine whether the EGR valve is seated or the EVP sensor is in contact with the EGR valve stem.

Possible causes:
-- Poor continuity in EVP sensor harness.
-- Non-seated EGR valve.
-- Damaged EGR valve.
-- Damaged EVP sensor.
-- Damaged EVR solenoid.
-- Damaged processor.

Service Code 624 indicates a failure of EPC circuit.

Possible causes:
-- Open or short in harness.
-- Resistance out of limit in solenoid.
-- Damaged processor.

 

By the way is your ABS light on?
Does the speedometer work OK and steady?

 

I forgot to the E40D info...yes...it has the OD button on the shift lever! and Yes, the speedo works fine and is consistent, the abs light does not come on.

Thanks so much for the help, you guys saved me a ton of leg work!

Greg