99' 3.0L Crank, No Fuel

[GPThomas]

I was hoping someone could help me out..... I have a 99 Ford Ranger 3.0L that will crank but won't start. I was leaving my house and suddenly the truck stalled out. It will crank but there is zero fuel pressure. I towed it home and have tried two different code readers to check for possible codes but neither will connect (No communication) to Forescan. I have jumped 12v to fuel pump and it will pressurize, but still will not fire up. When trying to start by key, the truck just cranks, but the fuel pump will not turn on. I've chased 12v to the fuel relay, but it does not pull in (energize) to pass the 12v to the inertia switch?

I have 12v on pin #16 and good grounds at #4 & #5 at the DLC...

Jumped #30 to #87 on fuel pump relay and pump turns on which leads me to believe, PCM is not grounding fuel pump relay for some reason...

I also show a 1:6 code on my pats system. I've swapped out keys, transponder, pats module and PCM from another 99' with the same results (1:6 code) on the theft light.

Any help would be greatly appreciated!

Thanks, Greg

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[RonD]

Welcome to TRS

When you turn on the key the CEL(check engine light) on the dash should come on, this means the computer(PCM) has booted up
No CEL = no computer

PATS issue would prevent starter motor from working, so not a PATS issue, and PATS code 1:6 means no communication with PCM
And the fact you can't "talk" to PCM with a reader would mean its off
So I think thats the issue

Fuse #8(30amp) in engine bay fuse box powers the computer via the PCM relay, you can swap PCM relay with Blower Motor relay

Fuse 19(25amp) in cab fuse box powers PCM relay activation with key on

You can get your owners manual here: https://www.ranger-forums.com/general-technical-electrical-18/ford-ranger-owner-manuals-1996-2011-models-3747/
Has fuse and relay layouts

 

[GPThomas]

Fuses #8 & 19 test good (12v and 0.2 ohms out) and when I Pull, #19 out, I can hear ECM relay kick out as well.

 

[RonD]

And the CEL?

 

[GPThomas]

CEL light is not illuminated

 

[RonD]

Then Computer(PCM, ECM) is not powered on

 

[RonD]

PCM is located in the upper firewall in engine bay, it has a larger 104 pin connector, can't miss it, lol

Has a bolt that holds on the connector
Disconnect one battery cable first
Remove that bolt and then pull off the connector, wiggle it back and forth, may need to remove some wire holders and/or tie straps

Pin numbers seen here when looking into the connector with the wires: https://www.2carpros.com/images/question_images/288731/original.jpg

Pin 2 should be a Pink/green wire just to confirm you are starting at the right place/orientation, this is the CEL bulb wire, just FYI

Pins 71 and 97 should be red wires, these are the 12volt wires that come from PCM Relay
Hook battery back up
Turn on the key
Test these pins/wires for 12volts

Pins 76, 77 and 103 are Grounds, test that these are 0 ohms to ground, black/white wires

If you have the 12v on 71 and 97
And 76, 77 and 103 grounds are good then PCM is a dead duck, failed, kaput

But unhook battery again
Plug connector back in
Hook up battery and turn key on to see if CEL comes on, if so the connector had corrosion on its pins, bad connections
Unhook battery
Pull off connector and spray connector and PCM slots with Contact Cleaner

 

[GPThomas]

Thank you for the help, Ron!

After spending the entire weekend on this truck, I was able to finally get it running again!!! After pulling the 104-pin connector off and going through the above steps, my CEL light came on.

Truck would still not fire up, but I was happy to see my PCM was not dead. I found another test online, checking voltage between outer pins on the throttle position sensor which only showed (1volt) after going through the 3 wire sensors, I disconnected the EGR pressure sensor, and my (6v) voltage was back! DLC was now communicating with the PCM and truck fired right up!

Learned my lesson on inexpensive parts online, because I had just changed that part out this past December because the PCM was throwing a related code.

Thanks again,
Greg