Hey I have codes 98 and 54.

I replaced the ACT sensor lastnight (code 54) but I still get the codes.

Codes 98 is: Failed KOEO test (didn't get code 11 = everything is ok) and it could mean the EPC solenoid is bad.

After i replaced the ACT sensor, I started the code reading process again and pulled the jumper wire out to reset the codes. The check engine light would go off...then come back on shortly there after.

However the check engine light would stay off if I left the jumper wire in.....

I bought this truck for $600 in Nov 2009 and this is the first time it's giving me some problems. Good little truck. I did a search on here and found a thread about the EPC being located in the transmission belly pan - but that was in the F150 section.

This truck didn't come with a service manual - so I have no clue where the EPC solenoid is.

While driving, the MIL light used to flicker and then go off and I would get OD back. But now - as long as it's on, The truck (A/T) won't shift into OD and it just drinks gas.

Does anyone have a pic of where the EPC solenoid is so I can attempt to replace it? Or a how-to or something?

Thanks,
Derek
Northern Virginia

 

bump thanks

 

What engine do you have in it?

 

My info suggests that a code 98 indicates a hard fault probably referring back to the ACT system. Where did you get the info suggesting a trans code because that's where the EPC solenoid is located.
The code 54 suggests the ACT sensor input is greater than Self Test maximum. It does not have to be the sensor itself.,,,,,,,hanky

 

thanks Hank.

I used a DVOM and got 13v at the ACT sensor.
Engine running - put the neg/pos poles of the DVOM in the pos/neg ends of the sensor. I believe I am only supposed to get 5v.

I have the 2.9L V6 A/T 4x4

I got the EPC info from a fault code list under the code 98. I suspect the EPC because the truck will not shift into OD while driving.

I looked at the wiring diagram and noticed the ECT sensor, ACT sensor, TPS, and MAP all share the same ground. I'm guessing there is a bad ground somewhere between those sensors.

Code 54 suggests the ECT as well as the ACT.

98 is (with the engine running)
- Did not pass the Key Off Engine Off test (supposed to get code 11 (two flashes = systems ok)
- Transmission EPC circuit/solenoid failure - Transmission

54 is Intake Air Temperature (IAT)or Vane Air Temperature (VAT) signal high - ECT (Engine coolant temperature)

got those codes from here http://www.therangerstation.com/tech...igitcodes.html

 

I believe you have a short to power. You are correct when you stated your veh ref voltage should be 5 volts. I'm trying to locate the terminal at the ECA that feeds the 5 volts. Somewhere i suspect you are feeding battery voltage to the ACT sensor . Can you trace the wires from the ACT sensor and see if there is some way that the wrong voltage is getting to it? If you opened the wire that is feeding the 13 volts to the ACT sensor and temporarily jumped a 5 volt reference wire from one of the sensors close by it should help confirm the short. Then rerun the KOEO test and see if that doesn't get rid of the code.
If you had a problem with the EPC solenoid you would have more problems than no overdrive. That solenoid is pulse width modulated and I can't see at this time how it fits into the picture.

 

I checked the only power wire from the ACT - it runs directly to the ECU. I checked for continuity between those 2 points and got tone.

Not sure I understand what you mean by opening the wire. It is a 2 pronged wire going into a connector that plugs into the ACT sensor - only way to open it would be to cut it.

Here is a wiring diagram that was provided to me. You can see the blk-wht wire that is shared with other parts inlcuding the ACT. Because my check engine light used to flicker - that is leading me to believe there is a wire-to-wire short or a broken wire between those sensors that are all share that same blk-wht wire. Would you agree?

Also - when I would jump the STI connection and SIG RTN connection to get the codes - if I leave the jumper wire connected - the check engine light would go off after the MIL light goes through it's blinking. Then, during the blinking, I would pull the wire to erase the codes and it would stay off for a few seconds, then come back on.....futhering my thinking that I have a broken ground somewhere since the STI and SIG RTN share the same ground with the ACT, MAP sensor, TPS, and ECT.

 

I am using a schematic from an authorized Ford Instruction manual. It does not correspond with the schematic you have displayed. I have yet to see a veh ref voltage from the ECA higher than the usual 5 volts applied to a sensor. Yes I did mean to cut the wire and my schematic shows MAP, TPS ECT, ACT all supplied with vef ref voltage from same source.
That is why I suggested to cut the present supply to your ACT and jump a reg 5 volt vef ref line to it.

 

hmmm ok thanks again!

just so I'm clear:

cut the power wire to the ACT sensor
jump in a 5 volt vef ref line to it. Is this something I go buy or just use some spare wire? Never done that before and I would like to fully understand before I go cutting wires.

Thanks again for your help.

 

I don't blame you for being concerned with cutting wires, but you should not be applying battery voltage to the ACT sensor. From what I see in the diagrams I have , the veh ref voltage (5 volts) is the only voltage applied to those sensors. As i see it, if you cut the wire at a convenient place to reconnect if necessary, locate another sensor wire that you verify is at the correct voltage, 5 volts, just use a straight pin and tap into the 5 volt wire and run a piece if insulated wire to the end of the ACT wire going to the ACT leaving the 13 volt wire connected to nothing. I would check once more to verify that the cut 13 volt wire is still reading 13 volts with the key on.
If nothing has changed start the vehicle and see if you get the C/E lite anymore.
You may have to disconnect the battery to get the lite to go out before starting the check. If 13 volts didn't destroy anything , 5 certainly won't. Let me know how you make out. hanky