I have a 1994 F150 302 5.0 efi and I took it up to O'Reillys since I've been have idle problems and apparently it has the codes 40, 538, 536 and 632 could any one please translate these for me because I have no idea what they mean. Thanks.

Code 40:
SERIES FUEL/AIR INJECTION CODES ON VEHICLES WITH DUAL OXYGEN SENSORS REFER TO THE RIGHT OR REAR SENSOR. EXCEPT: 1984-1988 3.8L ENGINES: LEFT SENSOR
(I only have 1 o2 sensor)

Code: 538
(R)
System did not receive "goose" test – TESTS


Code:536
(O,R,M)
Brake On Off open or shorted to ground – BOO


Code:632
(R)
E4OD – Transmission Control Switch (TCS) should be cycled once between engine ID and Goose test

Someone please interpret these for me...

 

Sounds like when they ran your KOER test they did not follow the procedure. The code for O2 sensor is the one to be concerned about. Might want to get another opinion at another store or shop.

 

These are all KOER test, first off what you have down as "40" is actually just 4-which is signalling that your truck has 8 cylinders (I-6=3, 302/351=4). The rest of your codes are telling you that you didn't follow any of the directions in the test, smashing gas to floor, pressing brake, OD button pressed. Read the thread that's sticky'd written by JCMS about pulling codes, there is a walk through on doing the running test, read it a few times and write down when to do what. It may take a couple of tries the first time but you'll get it.

A tip: you will only ever get 3 digit codes or 2 digit codes (depends on year/engine on which one) never a mixture. Also, codes are always given in numerical order. Recording the flashes with the video camera function on your phone is the easiest way to do it, you can record the flashes (the entire set of codes will be shown twice) then watch it with a pen/paper to write them down instead of trying to remember what to do while you are counting flashes.

Once you have the codes recorded, start the test again (KOEO test will work for this), this time pull the jumper wire/paperclip out while the codes are being displayed. This will erase all of the codes without deleting important data from the PCM (which unplugging the battery will do).

Test TPS for proper voltage (also very important that this is a Motorcraft part, if not replace it with Motorcraft).

 

How do I test it for proper voltage and what is the proper voltage?

 

Using a volt meter, clamp or secure ground to bolt, probe the wires going to the TPS with the red probe, do this with key in the on/run position but engine off.

Readings should be:
.9-.97v closed throttle
5v WOT
with a smooth increase as you open the throttle.

If you readings are close to spec you can loosen the two screws/bolts holding the TPS and rotate it slightly one way or the other until you get it in spec. It is possible to drill out the holes for greater movement/adjustability but this should only be used as a "limp" until you can get a replacement. There is also a specific procedure to follow when installing a new TPS, something about putting it in upside down then rotating 180*, not sure on that but you can google it for a walk-thru.

 

I just bumped "testing the TPS" up to the top. Never mind all the crap aktech had to say - I can't even follow what he wrote, so I wouldn't expect you to. Get a 15 - 20.00 multimeter, set it to volts Dc, 20 if it goes that low and just follow the directions.
Use the pointy end to pierce the wire.
I always seal the hole with a little dab of silicone after, but that's just being fussy.