PATS Issues on Engine Swap

[1978Cobra2]

Hey everyone, I am pretty deep into an engine swap and am pretty much at a road block. The details are, I have an 01 3.8 and manual transmission going into a 1977 Mustang. I am transferring pretty much everything over to the 77. So far I have the ECU, Cluster, OBD, PATS transceiver, Fuel pump module, and the relay box for fuel pump and fans hooked up.

My problem is, when I power up the ECU I get no theft light at all. To do what I have done required a lot of cutting in the harness, but I have full schematics of all the individual systems. With this, I have been able to power all of the necessary power wires to the ECU, Cluster, transceiver, and everything else that needs power. Also, all of the grounds have been wired in as well.

As far as transceiver wiring goes, it goes from the transceiver, to the cluster, and the only thing else I see are what is labeled as "Computer Data Lines" which then run off to the ECU as well as the ABS module and the OBD port.

As far as I can tell, the THEFT light should flash regardless if there is a key in range of the transceiver or not. But I am not getting anything at all, which indicated to me the system is not functioning and therefore is cutting fuel injectors/pump signals.

What am I missing? The only thing that is not in place is the ABS module, i'm not sure how that would interfere with the theft system. I know with all the wiring there are a lot of variables, but i'm running out of ideas.

Thanks for any help, this really halts the whole project!!!

 

[wicked93gs]

I have to ask...why are you using a a PATS EEC computer to run the 3.8L to begin with? I am assuming this is the standard Essex v6 that has been around decades correct? You should be able to run the thing just fine off of an EEC IV ECU that doesn't have PATS...its a pushrod v6 with a distributor and a 36-1 crank trigger...earlier versions used an EDIS-6 module for ignition control....that right there sounds like a perfect candidate for Megasquirt.

 

[1978Cobra2]

I'm using the PATS computer because that's what was in the parts car I bought, just trying to transfer everything. As far as using another computer that does not have PATS, I would have to find one that works with a return-less fuel system so the fuel pump module can work correctly. (I'm also swapping the 2001 fuel tank into the 77). As far as I can tell the previous year 3.8's that do not have PATS all ran a return fuel system. This particular 3.8 does not use a distributor but rather a Cam position sensor.

I'm looking into a "PATS delete" Tune for my ECU now, and worst case I will go with building my own Megasquirt. Just trying to get the stock stuff to work since i've already got loads of time invested in it.

Thanks for the feedback

 

[wicked93gs]

Your existing fuel pump should work just fine in a return style fuel system....I don't know what all is included in the "module" you may or may not need to bypass though. You are on to the correct solution though...I know of one tuning shop off the top of my head that can eliminate PATS in the later ECUs...at least for EEC5

 

[wmburns]

If asking for an educated guess, how about no communication between the cluster and passive anti-theft transceiver modular. Want to know for sure? Use an advanced ODB2 scanner to "talk" to the cluster and find out IF the cluster "sees" the transceiver.

Here's some information on an affordable Windows based unit.

ForScan ODB2 scanner w ELM327 USB

ForScan ODB2 scanner w ELM327 USB

While working on your car have you ever wanted: to find an ODB2 operational PID value (say fuel pressure or MAF)? How about graph a PID value over time? Or compare multiple PID's over time? Access a bi-directional PCM control such as test a...

www.stangnet.com

IF the reason for the crank with no start THEN there should also be an anti-theft specific DTC code stored in the PCM.

But what have you done to rule out something simple such as a burned out theft light?

Another option is to use the ODB2 scanner to "command" the cluster to turn on the theft light.

 

[1978Cobra2]

If I kept the stock pump and used a return style ECU, I wonder if it would work the pump like it should, or would I have to convert the whole fuel system over to a return style. If it would work either way, I guess I could grab a ECU out of a non-PATS 3.8 car from the junkyard. I'm pretty sure the E series vans did not have the PATS system for a while. Maybe an ECU out of a 4.2 E series would work? I'm gonna call some tuning shops tomorrow and see what I get.

Possible that the light burnt out, but I do remember seeing it on the parts car, I bought the parts car and actually drove it a around town for a bit. As far as the scanner, I should have access to a decent Snap-on scanner, just not sure if this will be setup to read the instrument cluster, as iv'e seen only certain makes or models can do that.

Also, "wired" in the ABS module tonight, no change. There's only one possible thing left and that the General Electronics Module. Which Is a lot of work to splice in for temporary purposes and looking at the wiring diagrams I do no really see a relation between that and and Anti theft.

Thanks for the replies!

 

[wmburns]

Possible that the light burnt out, but I do remember seeing it on the parts car, I bought the parts car and actually drove it a around town for a bit. As far as the scanner, I should have access to a decent Snap-on scanner, just not sure if this will be setup to read the instrument cluster, as iv'e seen only certain makes or models can do that.

I suspect that any high end ODB2 scanner that also supports manufacturer specific di-directional support will also be able to talk to the cluster as well.

 

[1978Cobra2]

Next time I can borrow that scanner I will give it a shot!

 

[wmburns]

If I kept the stock pump and used a return style ECU, I wonder if it would work the pump like it should, or would I have to convert the whole fuel system over to a return style

If I understand this there isn't a return line after the fuel pressure regulator. If this is true then the fuel pressure will be chronically HIGH.

In a correctly working 1996-1998 Model year the PCM should "prime" the fuel pump at initial key on. Then will shut off until the motor has been "sensed" as running.

At the trunk mounted IFS confirm there is +12 volts at initial key on and then off.

Note. PATS does NOT disable the fuel pump. It works by with holding the fuel injector pulse. So if the fuel pump isn't priming the reason is NOT PATS related.

 

[1978Cobra2]

When I first started checking at the fuel pump, I was looking for the initial prime when I powered everything up (essentially key on). As it turns out, on a return less fuel system, at least on this 01, it will not prime the pump. When it sees the engine crank signal it will command the pump on deliver the pressure. This is a little harder to diagnose considering the harness is out of the vehicle and cannot directly trace to individual components.

I've done a bit of research on the PATS system and apparently it depends on the year and model. Certain vehicles only had the injector pulse cut, while others had both the injector and fuel pump signal cut. I think some would keep the engine from even cranking at all. I believe this 2001 to have it where it cuts fuel pump and injector pulse.

Before I even got to the fuel pump I wired everything up and checked the injector pulse with a noid light and power probe and have no pulse. Only battery + and a solid ground, no signaling. I do get proper spark output so I know that it's reading the sensors correctly. But that's when I suspected I was going to have an issue.

 

[wmburns]

Did you also install the fuel pump driver module? Are the control wires in place between the PCM and FPDM?

I promise you that a normal 1996-2004 will prime the fuel pump for a few seconds at each key on. That's how the fuel pressure is built up high enough to allow the motor to start between key on and cranking. This fuel pump prime is an important trouble shooting step that help to confirm the PCM's ability to control the FPDM/fuel pump.

If you are not getting the initial key on fuel pump prime this is an important symptom and should not be ignored. Only a Mustang older than 1995 will disable the fuel pump as part of the anti-theft PATS response.

Again. IF PATS is the reason for the crank with no start, THEN there will be a DTC code stored in the PCM.

 

[1978Cobra2]

Yes fuel pump driver is installed and wired to all the corresponding wires in the harness per the diagrams. No fuel pump prime when the ECU is powered up. I can pin to the control wires and see 5v reference, a ground (which i believe is signal from ECU) and another wire that has 6.5v (labeled fuel pump driver on the diagram)

The only code stored that I can currently read is a P1233 which looks to be fuel pump related.

I wonder if I have a cluster communication issue, I read somewhere most of the PATS system works in the cluster. I have odometer reading as well as an engine light.

 

[wmburns]

Smoking gun alert! ^^^This is why all DTC codes should always be posted.

For some reason the PCM is not receiving the duty cycle signal from the FPDM. That is why there's key no fuel pump prime and the reason for the P1233 DTC. Find out the reason why and I suspect things will change for the better for your project!

I also suspect there's an unrelated reason for the no cluster theft light. Positive. This is not a PATS issue.

There are a series of pinpoint test (KB) in the Ford service manual to trouble shoot the FPDM. The tests start out by verifying powers and grounds to the FPDM.

>>From Ford service manual.

P1233 - Fuel System Disabled or Offline​ All Others: The PCM monitors the fuel pump monitor (FPM) circuit from the fuel pump driver module (FPDM). With the key on, the FPDM continuously sends a duty cycle signal to the PCM through the FPM circuit. The test fails if the PCM stops receiving the duty cycle signal.​ ​ Inertia fuel shutoff (IFS) switch needs to be reset Open FPDM ground circuit Open or shorted FPM circuit Damaged IFS switch Damaged FPDM Damaged PCM Also for Escort/Tracer and Mustang: Open FPDM PWR circuit Open B+ circuit to constant control relay module (CCRM) pin 11 Open ground to CCRM pin 18 (Mustang) Damaged CCRM Also for Continental: Open VPWR circuit to FPDM The PCM expects to see one of the following duty cycle signals from the FPDM on the FPM circuit: 1) 50% (500 msec on, 500 msec off), all OK. 2) 25% (250 msec on, 750 msec off), FPDM did not receive a fuel pump (FP) duty cycle command from the PCM, or the duty cycle that was received was invalid. 3) 75% (750 msec ON, 250 OFF), the FPDM has detected a fault in the circuits between the FPDM and the fuel pump.​

 

[1978Cobra2]

I'm gonna go double check all my connections and see if I come up with anything.

What do you think would cause the lack of signals to pulse the injectors?

I just went out and double checked all the connections. According to diagrams they are all correct and all check out in accordance to the service manual clip you provided. Here is what I am seeing now:

I am completely bypassing the IFS switch as well as the CCRM and directly powering the the FPDM. When this is powered, both wired to the fuel FPM have battery voltage, when I give one a ground the motor runs. This tells me It is looking for a ground, which I imagine would be a signal from the ECU. Also, when I power the FPDM, even the the ground wire directly out of the module is hooked to battery (-) it will carry battery voltage. This does not make sense to me.

 

[wmburns]

This does not make sense to me

It may not make sense because there's an incomplete understanding of HOW the CCRM, PCM, FPDM, and fuel pump itself integrate to each other. The problem is not in the CCRM itself. The problem is that the PCM is NOT "seeing" the expected digital feedback signal from the FPDM.

I am completely bypassing the IFS switch as well as the CCRM and directly powering the the FPDM

The motor runs when the CCRM is forced on "proves" that much of your work is good. However it's not a viable long term solution because it bypasses the PCM's control of the FPDM. This will result in chronic high fuel pressure and all the problems this will bring with it.

Do you have an advanced ODB2 scanner? Do you have the ability to monitor ODB2 PID's?

Do you have a Ford Service manual? There's a very detailed set of pinpoint tests to trouble shoot a FPDM. If interested in getting a copy for yourself I maybe able to help. PM if interested.

 

[1978Cobra2]

The only time I get the motor to run is when I bypass the FPDM, so you're right there is no feedback or signal happening to make the pump run.

To me, bypassing the CCRM wouldn't result in full fuel pressure because that should just power the FPDM through a relay, all the modulation would be done through the FPDM.

I am going to get an advanced scanner today and see if I am able to read any more codes that maybe my little handheld cannot see. I will also see if there are any PID's for fuel pump, like the duty cycles.

I will retrace my steps, and do a few more tests, then maybe ill see about getting the service manual.

Thanks!

 

[wmburns]

To me, bypassing the CCRM wouldn't result in full fuel pressure because that should just power the FPDM through a relay, all the modulation would be done through the FPDM

IMO what you are missing is there are NO sensors inside the FPDM to allow the FPDM to control fuel pressure. The FPDM does NOT control fuel pressure directly. It's the PCM that controls fuel pressure via signals sent TO the FPDM.

The PCM is also expecting a feedback signal from the FPDM. This bi-directional communication is necessary in a return-less fuel system.

It's your project and you can do what ever you want. But IMO if you force the FPDM to run on it's own with no PCM control/feedback the only logical outcome will be fuel the maximum fuel pressure that the fuel pump is capable of delivering. This will create other problems such as:

• The fuel pump working against maximum head pressure when the motor is not running.
• heating of the fuel from the pumping action of the fuel pump with no cooling effect
• the PCM will "detect" the sky high fuel pressure and attempt to compensate via shortening the fuel injector pulse. However there are limits to the minimum injector pulse width that the injectors are electrically and mechanically capable of responding to.
• A chronic check engine and outstanding DTC code which you have already seen.

If considering an advanced ODB2 scanner make sure that it reads more than generic ODB2 PID's. It needs to be able to read manufacturer specific data PID's to give the best picture of what's going on. Don't get me wrong. Even having access to generic ODB2 data is better than nothing. At least this would show you what the fuel rail pressure sensor is reading. This is useful because then you will actually know for certain what the fuel pressure is.

Good luck. Sounds like a cool project. You maybe very close to getting it to work.

 

[1978Cobra2]

Hey Thanks!

As far as bypassing everything to the FPDM it is just temporary for troubleshooting purposes. But yes, the PCM does send the single the the FPDM for the desired pressure.

Hooked up a scanner to it today and found more codes that are pointing me in the right direction I believe

B1202 - Fuel sender Open Circuit
B1600 - (PATS) Ignition Key Transponder Signal Not Received
P1260 - Theft Detected, Engine Disabled
P1233 - Fuel Pump Driver Module Offline

I blame the P1233 on not having any of the fuel system wiring hooked up when putting the harness together and powering up the ECU.
Not sure what B1202 has to do with anything or why it showed up as a B code in the "Anti Theft" section of the scanner.
The other two codes are really pointing me to a anti theft issue.

Also, like you said, I was able to command the Theft light on, although, it would still not light. Not sure what I am missing that is not allowing the light/system to activate.

 

[wmburns]

B1202 - Fuel sender Open Circuit
B1600 - (PATS) Ignition Key Transponder Signal Not Received
P1260 - Theft Detected, Engine Disabled
P1233 - Fuel Pump Driver Module Offline

IMO you have TWO problems. The B1600 indicates that the cluster is NOT "seeing" a valid transceiver signal. The P1260 is a symptom of the base problem. IE the default action of PATS is to deny fuel. There are cluster PID's that will give you an idea where the process is breaking down.

The first step in the Ford manual under pinpoint test "F" is to program a new PATS key (after verifying powers and grounds). If this doesn't fix the issue, install a new PATS transceiver. Because you have done so much wiring work, IMO you should verify a good signal wire path.

It seems to me that the no theft light may or may not be related to the base PATS problem. But I wouldn't ignore the possibility.

At the PATS transceiver module, check for key on power on pin #2 WH/LB. Check for a good ground at pin #1 BK/WH. Best to use a test light that will "load" the circuit. Cluster Pin #7 GY/OR and pin #8 WH/LG handle the communications to the transceiver.

If this were my car I would be looking very close at the cluster printed circuit edge connector. Look for damaged PC foil trace.

Note, the presence of the P1260 gives verification that the reason for the no injector pulse is PATS related.

The P1233 is from the break down of bi-directional communication between the PCM and the FPDM.

The B1202 indicates there's an open in the wire path between the cluster pin #19 (YE/WH) and the cluster.

Just wondering. Have you posted this problem on other Mustang forums? Are you getting similar help elsewhere?

 

[1978Cobra2]

Tomorrow I will definitely look more into the connection between the transceiver and the dash.

As far as programming a new key, from what iv'e seen, on this style I would need two keys, I only got one from the previous owner of the parts car. Trying to keep on a tighter budget, after talking to two tuners, they say it is completely possible to have a tune written that deletes the PATS system. It's looking like the route I am going to take, because after all, eventually I will need a tuner. (this is suppose to be a turbo car)

This is the only place iv'e actually asked for help, other wise I have just been reading about the systems and studying wiring diagrams. Thank you for all your input!