Hey fellas. So i picked up a project and i am totally stumped. 03 ranger. Not sure if problem was already there but heres what i did. Guy busted up ignition due to key being taken away (DUI) I buy the truck and replace steering column. Go to program the new to to ecu and no communication. Ive disconnected quite a few sensors. Fuses seem fine. Ecu looks good. What the hell is going on?! PaTs light fashes about every two seconds or so.
Jj.hawk1@yahoo.com thannks for any help boys.

 

Welcome to the forum


Fuse #17, 20amp, in cab fuse box powers OBD2 port, it needs power for OBD2 reader to work


PCM(ECU) also needs to power up
Check engine light(CEL) will come on if that is happening when key is turned on.
No CEL means PCM is not booting up, or burned out bulb, or check fuse #11 in cab fuse box, 7.5amp

PCM gets power from PCM relay in engine fuse box closing, ignition switch ON closes PCM Relay
PCM Relay also powers up the fuel injectors and coil pack, also several other sensors and controls, you can test one to make sure PCM Relay is working
Fuse #7 in engine fuse box, 30amp

Theft light on dash is grounded by PCM so if it is flashing slowly back up power for PCM is working, thats fuse #21 in engine fuse box, 10amp, this can't power up PCM it is just to hold memory and keep theft system active

 

RonD thanks. CEL is not lighting up with ignition. All fuses are good. Looks like PCM may not be booting up. Any advice as to testing PCM its a 3L5A-HE

 

Well if previous owner jimmyed the key he may have done the same for CEL

Theft light flashing mean PCM is partially working.

Theft light should stop flashing if PCM is booting up

A few wires you can test, red wire on coil pack should have 12v with key on, same 12v PCM gets

Throttle position sensor has Brown/white wire, it should have 5volts from PCM, that means PCM is getting startup voltage


Does your OBD2 reader power on and just not connect?
Or does it not turn on at all?