'99 5.0 in a '96 Ranger, PCM and fuel pump issues.

[540milotalon]

I know some of the members on here are members on other sites too. I am reposting here from another site.

Not sure I can make this short.
I swapped a '99 5.0 from an Explorer into a '96 Ranger.
Ranger V-6 runs at aprox. 36 psi fuel pressure. '99 Explorer operates at 58-60 psi. I am using the Explorer higher pressure fuel pump and regulator on the Ranger hanger, in the Ranger tank.

'99 Explorer has PATS, '96 Ranger dos not. I downloaded a wiring diagram, to wire in the PATS transmitter, receiver and zip tied the key to it, supposed to make '99 PCM think it's the Explorer still, did NOT start. Fuel pump does NOT run with key on, not even a couple seconds pre-start. Fuel pump works and pressurizers the line with jumper wires, either directly to pump or removing relay and jumping at the fuse box. Could this be as simple as the only key I have no longer working?

I swapped in a '96 PCM purchased as a reman from auto parts and the engine started right up. Very sudden, and ran until out of fuel. repeat pressurizing the line, unhook, starts up, runs out of gas. The '96 5.0 Explorer PCM will not power up fuel pump. I did not keep it running as it has no coolant in it.
Last night I plugged my Autoenginuity up and ran some tests, looked for codes. Stored codes of reference, P0230 and P0232.
P0230 is Fuel Pump Circuit Primary circuit malfunction, P0232 Fuel Pump Secondary circuit high. A/E was looking at truck as a 1996 Ranger. Cleared stored codes I ran KOEO test and as part of test, the fuel pump cycled.
Reinstalled the '99 PCM and as part of KOEO it did NOT energize fuel pump and gave the P0230 code. Swapped the '96 Pcm back in and told A/E it was '99 Explorer it energized the fuel pump on KOEO and did NOT throw a P0232 code "High Secondary Circuit"
However, it started and ran several times on Tuesday, now, as of yesterday it no longer starts and runs.

I believe the '99 PCM is keeping the fuel pump and injector circuit open because the PATS was not bypassed.
I believe now the '96 PCM is locking out the Injectors because the fuel pressure is too high (it thinks)
Wiring from key to fuse box/relay/inertial switch/pump appears intact.
Is there a place that can reflash my '99 PCM and take PATS out of it?

Short of using C4 is there anyway to take care of my problems?

 

[RonD]

There is no fuel pressure sensor for either of these PCMs

Both codes were set because of the testing you did
P0230 is because FP Relay was unplugged/removed and key was turned on
P0232 was set because FP relay was jumped or fuel pump's 12v wire had 12v with key on, and PCM was not activating FP Relay at that time
So ignore them, for now

The 1996 PCM should allow engine to start even with the higher fuel pressure, it will just run RICH and then set Rich codes once O2 sensors warm up

Unplug the Cam sensor, it may be causing an issue because its a 2 wire model and 1996 PCM needs/used 3 wire model

Try 50/50 test
Spray fuel into the intake and crank
If it starts again then you still have a fuel delivery issue
If it doesn't start then its a spark issue now
50/50 instant results

 

[540milotalon]

No, it throws those codes with all relays, connectors in tact. Clear codes and run KOEO test with '96 PCM, tests ran on a '96 Ranger=the PCM energizes pump and throws P0232.
Clear codes, using '96 PCM, tell A/E the truck is a '99 Explorer and it cycles fuel pump during KOEO test but does not throw P0232.

I am not sure what is going on, but it quit starting up.

 

[RonD]

OK, do 50/50 test to confirm its a fuel issue or its now a spark issue

 

[540milotalon]

Truck only starts now with spraying carb cleaner in the throttle body/intake. Air cleaner removed.
Tuesday using the reman 1996 5.0 Explorer PCM it would start and run on its own until it burned off the fuel in lines, it longer will do that.

 

[RonD]

Good, so its a fuel delivery issue

Forget the past, work the problem, pick a PCM and stick with it, I would use the 1996 since there is no PATS
Unplug the Cam sensor

Do you hear the fuel pump come on with key on?

 

[540milotalon]

No, fuel pump only works during KOEO test with ‘96 PCM, never with ‘99. I am having another’96 brought in today since this one quit allowing the engine to start with fuel in the line. I can unplug the cam sensor when I get back to the shop. Will report back.

 

[RonD]

The 1999 engine cam sensor is 2 wire and 1996 PCM can't use it, not sure it would effect startup but its unusable so best to leave it off, it is used for fine tuning fuel injector timing after start up, but engine will run without it

If fuel pump runs for the 2 seconds with key on
And engine starts with 50/50 test
Then fuel injectors are most likely not being grounded by PCM

That can be caused by Cam sensor(maybe), but also TPS(throttle sensor), so unplug the 3 wire TPS as well

All fuel injected engine computers have a "Clear Flooded Engine" mode
Ford, and most others, uses
Key on
0 RPMs
TPS Wide Open(gas pedal to the floor)
This tells PCM to shut off injector pulses, its now in "Clear Flooded Engine" mode

So cranking engine at this time will dry it out with max air flow and no fuel being added
Releasing the gas pedal starts injectors

A shorted TPS or its wires can cause a no start, on purpose

 

[Mechrick]

The '99 Explorer uses a standalone PATS module behind the passenger airbag. Did you wire it in? When swapping modules it's common to have to perform a 'Parameter Reset', and maybe a key learn.

-As far as the codes, they indicate an open circuit after the fuel pump relay *and* a problem on the primary side of the relay. The PCM grounds the fuel pump relay from pin 80 to turn it on. The FP Monitor in the PCM (pin 40) is tied to the output of the fuel pump relay. When the fuel pump is commanded on, the PCM sees 12 volts. When the fuel pump is commanded off, the ground path through the fuel pump motor windings is supposed to pull pin 40 to ground.

-If there is an open anywhere in this circuit between the pin of the relay and where the fuel pump grounds (g200, somewhere behind the left kick panel) the circuit floats up to 12 volts and you will get a no start and these codes...

 

[540milotalon]

I have the wrecked donor ‘99 Explorer and used the transmitter ring from lock cylinder, the module behind Explorer glove box and zip tied key to ring. Wired per diagram including key on hot and constant hot. Used frame ground from under dash . I dunno.

 

[RonD]

If you can hook up a Theft Light(test light) to the PATS module it will flash a 2 digit code number telling you why the system won't allow startup

When PATS module gets 12v(powers up) it sends a radio pulse to transceiver(antenna around the key), the RFID tag in the PATS Key gets enough power from that to send out its tag number, antenna transfer that number back to module
PATS module compares the number to its "programmed numbers" if no match, then PATS module will flash Theft light Rapidly

Theft light will flash for 45-60 seconds and then start to flash a 2 digit code, a 1 and then 1 to 6, then repeat
11 Transceiver [transponder coil] not connected, or there is no power to it.
12 Transceiver internal fault.
13 No Key/no PATS key has been used to turn the ignition switch.
14 Incomplete key code received.
15 Invalid key code received.
16 CAN communications error

Your PATS wiring diagram should show a dark blue/green stripe wire going from PATS module to instrument cluster, thats the Theft light 12v wire, so if you ground a test light and hook it up to this wire you could first see if PATS is the issue, rapid flash, and then see what code is causing it

The transceiver is just a powered antenna, its not matched to PATS module or computer, so can be replaced with any other transceiver

 

[Dirtman]

Wouldn't a 99 computer be trying to set the injector pulse width almost 50% less than what the 96 fuel system needs to run?

 

[RonD]

Wouldn't a 99 computer be trying to set the injector pulse width almost 50% less than what the 96 fuel system needs to run?

It wouldn't be 50% but yes, open time would be less from 1999 PCM expecting 60psi pressure, but OP said he changed out the 1996 fuel pump assembly for the 1999 assembly with 60psi regulator

 

[540milotalon]

I don't know why this is so difficult?
I installed the "new" reman '96 PCM and the truck acted just like it did on the earlier one, will not start, will not cycle the fuel pump, at all. Truck will start with carb cleaner. Truck will not start with Cam Sensor unhooked ('96 PCM).

I wired back up the '99 PCM with a constant hot, a key on hot, wired up like the wiring diagram I do NOT have a flashing "theft" light using a test light. Is there something wrong with the PCM? The guy wiring it up?

I found a shop that said they could take PATS out of my '99 PCM, for $350. and turn around time 2-3 days! Then the tech guy called me back after seeing a pic with the FORD bar code and said it was a difficult one to do, would take 2-3 weeks because he sends it to a programmer and he thinks they can honor the $350. quote. Then he said he needs to know how many wires go to the; Crank Sensor, Cam Sensor, the specs on the MAF sensor because of the range. I do not have the '99 MAF set up, I have an earlier one. instead of 6 wires on the MAF like my connector, I have 6 wires but a 4 wire connector and a 2 wire connector. He cautioned I may need to go back to the junkyard.

Would it be easier to change a couple sensors and use the '96 PCM? Is that even possible?

 

[RonD]

No, its not this hard, there is something else wrong

So with 1999 PCM and PATS module hooked up the THEFT Light wire has 12v key on, and then goes OFF, thats what it should do
And then you should hear the fuel pump relay click and fuel pump run for 2 seconds, if PCM got the "OK to START" message from PATS module

And PATS module should also have grounded the Starter relay, so key should now work to start engine