2002 Ford Ranger 4L 5 speed Extended cab

It has spark but not fuel at the spark plugs

The relays seem to be good but there is no control, ground circuit from the PCM to the fuel pump relay, There is power to the injectors but no ground. There is continuity between the pin 80 and the fuel relay ground
Also no control to the starter relay
The PCM relay is working as is the diode.

I changed the fuel pump even though it worked when I put power to it or shorted the relay.

The PCM also does not seem to read properly. When I plug an elm 327 in it does not have any lights when not connected to the computer. It also does not connect properly to the computer. And no DTC codes, The check engine light does not come on

I Tested the pins on the PCM connector, There is voltage on pin 55 also when in run on pins 71, and 97
and ground on pins 24, 25, 51, 76,77, 103
The grounds show very low resistance, .1 or less
Voltages to the PCM connector are about 12.6. I did have a charger hooked up at the time just to keep my battery up
There is a pin 90 that is labelled reference voltage, I’m not sure if there is supposed to be power there or not but there wasn’t any during my testing.

It looked like every thing else should be fine so I changed the PCM

But, new PCM and same problem.

What exactly would cause my pcm top not work? Maybe no power somewhere or some component doing it? I’ve tried 2 replacements and neither worked.

Things I have tried so far:
Checked fuses/relays. Diode and Fuse boxes and No obvious fuse or wiring problems
Put power to the fuel pump
Changed the fuel pump, motor only
Cleaned all the grounds that I could find
Installed a new Battery
Bench tested the CMP
Changed the PCM
Added an extra ground from the ground by the pcm to the battery

It will crank by putting power to the relay or by grounding the ground to the engine compartment
Fuel pump also works the same way

It will also try to start if I spray fuel in the intake.

The wire s that go to the control side of the relays have continuity

 

​​​​​​Can you clarify this?

What does the anti theft light on the dash do when you put the key in and try to start?

 

Welcome to the forum

PATS(passive anti-theft system) is in all 1999 and up Rangers
It disables fuel pump ground and fuel injector grounds if activated, but spark would still work
On some years it also disables starter motor activation, but not all years

PATS uses an RFID tag embedded in a PATS Key handle
There is a "wand" around the ignition key slot that reads the unique number of key's RFID tag when you turn on the key
The Computer was programmed at the Factory with 3 or 4 PATS key numbers, the keys that come with a new vehicle
It compares the number from the key in the slot to numbers in its memory, if a match is found then Grounds are restored and engine can start
If no match then no grounds and no start

There is a Theft Light on the dash, if bulb is working it should flash every 10-30seconds or so with key off, it warns thieves that there is an active theft deterrent
Theft light can have "theft" on it, usually Red or look like a Padlock, red or yellow

If computer can't find a match for the Key in the slot then Theft light will flash rapidly with key on, if you wait 60seconds or so, that light will start to flash a CODE NUMBER
The Code Number can tell you why there was no match, could be the "wand"(transceiver) is bad, key number was garbled or its just the wrong key

Ford Dealer or Mobile Locksmith can make new PATS keys and program computer with the new number(s)

There is no way to by-pass PATS, even for a moment, wouldn't be much of the theft deterrent if there was

OBD2 readers can also get PATS codes, it would be a B1xxx or B2xxx code, a Body code number not a P, powertrain number, except for P1260 = PATS disabled fuel system, immobilizer active

 

if this is what you are asking
and elm 327 is an OBD II interface to hook up to a computer, then I use software like forscan to read the pcm
https://interfusellc.com/elm327/

Anyway, I think it should send some sort of power to a wireless elm so that it can connect to the computer. And have an LED indicater to show that.
but I'm not 100% sure as It is the first time I've used one. In the past I've just used a code reader.
In this case my code reader doesn't show anything either.

 

Thank you for the welcome RonD and for the reply.

I Went and looked, and there is no flashing anti theft theft light which I know there used to be one.
Maybe the bulb is burned out?

So the pats codes are inside the pcm?
What I did was I bought a programmed pcm with keys and there was a procedure to have the keys cut then insert them one at a time for three seconds.
https://www.fs1inc.com/2002-ford-ran...with-keys.html
But I didn't cut them and used my original keys.
Maybe this was a mistake.

I got a subscription to the forscan forums and i can get the version that allow PATS key programming
But that won't work if it won't connect to the pcm.

I have the steering column cover off and was about to test the connections, I see the electronic device just under the key.

If keys are programmed using the PCM, I think a reader should connect so that a guy could do so

I will go get those keys cut and see if that does the trick.

other than that?

What can I do to make this work? Is the only way to tow it to a dealer?
Or can I replace the light and transmitter by the ignition key

 

Couple of things you can do

Unhook the battery, either cable, first, this will reset PATS after about 5 minutes of no power

Take one of your old keys and turn ignition cylinder on,then pull it out, look up "how to remove ignition key cylinder on ford ranger", lots of videos on this
Take cylinder, old key and new keys to a lock smith, he can cut the new keys to fit the lock OR he can reKey the lock to fit the new keys, it depends on the keys.
If he reKeys the lock then you will need to use the old keys for the door locks or have them reKeyed as well

OR

Take an old key to any place that can duplicate keys, and have them cut a NON-PATS Ford key, so just a plain key no RFID Tag in the handle
Put one of the new keys near ignition cylinder and use the NON-PATS key to turn truck on and then start it, computer will read the PATS key if its near the cylinder
You can't use two PATS keys near the cylinder because BOTH KEYS will transmit their numbers so computer gets garbled numbers, not one clear number

Once the engine is started PATS is off line, so you can drive it to a Locksmith who can program new keys to the computer
PATS is ONLY used when key is first turned on, it can't disable a running engine, so you are fine until key is turned off, then you need to repeat above

If you do the above using a NON-PATS key AND you got two new working keys with the new computer, you can ADD your old keys to the new PCM.
Look up "how to add PATS Keys"
It is not hard to do, but if you only have one old key then I would get another made and add it as well

 

I will try as you say, Although if the original keys don't work of which I have two, I don't know how newly cut keys will.

However it is a shot that if I get the keys that came with the new pcm cut that they might work.

Thanks, will post my results after I get to a locksmith.

Suppose the PATS "wand"does not work, can I replace it with one from an auto wrecker?

 

The "wand" transceiver is just a powered antenna so can be replaced without any programming issues, so yes you can use one from a wrecking yard.

Original keys can rotate the cylinder, which the "new" keys can't, but the original keys are PATS so will broadcast their number when key is rotated
New PCM will reject that number, so no start
If you use a NON-PATS key to rotate the cylinder then one of the "new" keys placed near the "wand" will broadcast its number and PATS will allow start up

If you try that with original key then BOTH KEYS will broadcast their numbers and PCM just gets a garbled number, so no start
And this can happen by accident if you have two Ford vehicles with PATS keys
If you have both vehicle keys on a small key ring then BOTH KEYS will broadcast their numbers when you turn key on, causing a no start

 

You could also go ahead and replace the anti-theft bulb to ensure that you're truly dealing with a PATS issue. I think you are, but that would help confirm.

 

Yes, if you don't have one you can download your 2002 owners manual here: https://www.ranger-forums.com/genera...1-models-3747/

On page 10 it shows THEFT light to the right of Right Turn indicator
Most dash bulbs should light up with Key ON, it's a Ground Bulb Test, not a "system" test, just a bulb test.

 

I have an update.

I went and got those keys cut, then I stopped at the auto wreckers and got one of those transmitters, another LED for the theft and a switch where the wiring hooks into the ignition.

Anyway it turns out that the connector for a transmitter for a 03 ranger won't fit for a 02, but, the switch connector thing fit.

Anyway after fiddling with that stuff, I put the new keys in, one and then the other like what is done when adding keys,

Then it started right up.

Then I added my old keys too, all working.

I want to do some testing just in case it is a fluke, but it got too dark on me, maybe tomorrow.

There is probably still some thing wrong in that the theft light still does not flash, The interior lights now are not working. And the DLC connector still seems to not be working, will have to see about the rest tomorrow.

And I don't know which thing I did that ended up doing th trick, if any, maybe it was just shifting the wires around.

But the main thing is that it starts so that is awesome ! !

Thank you guys soooo much for the Help. You guys are Aces in my book.

 

I don't see a link for that owners manual, that would be nice to have.

Thanks again.

 

Good work

Sorry, forgot to post it, here's the owners manuals link: https://www.ranger-forums.com/genera...1-models-3747/
I added it to above post as well

Thanks for the tip on the '03 and '02 transceiver connectors, that's not something Ford includes in any literature, lol