BA Turbo - PCM & Fuel Pump Issues

[mc03]

I'm dealing with an issue on my 2003 BA turbo manual where the fuel pump relay is not getting a trigger signal from the PCM. The car is tuned with an SCT flash tuner, but this was done years ago, this issue is only recent. 

 

The fuel pump does not get a signal from the PCM to prime or run. Sometimes disconnecting the battery and letting the PCM reset will fix it, sometimes it won't, but eventually it stops working and won't work again until reset. 

 

The fuel pump and all its wiring after the fuse box is fine, the car runs without issue if I bridge out the fuel pump relay with a jumper wire. 

 

I have swapped and tested multiple relays and changed the inertia switch, didn't fix it.

 

The wires between the PCM and the fuel pump relay are fine (<1ohm), and all the PCM pins and connectors look fine, so I'm convinced the PCM isn't opening the ground signal to open the fuel pump relay (it does have 12v on the coil side). 

 

When it happens it throws code P0230 fuel pump relay primary circuit malfinction. 

 

Has anyone encountered this before and has any idea where to look next? Is my PCM dead?

 

Any advice is appreciated, thanks

[defkos]

Hi guys from PCMTEC, I these days sold a BA Xr6 turbo with a BTR, for the reason that I offered it I actually have had issues with the car stalling, it could occur at any circumstance however commonly as slower speeds, it's going to absolutely flip off the engine, at a few times it's going to simply stop accelerating, I can step at the throttle and not anything will manifest, however once in a while it will come lower back again, however at other instances I may not be capable of carry the revs up and it stall and stop completely. At times simply after it has stalled I will now not be able to crank the engine, it'll take a few attempts until the engine cranks and it starts over. I even have get admission to to ford IDS device and once I connect the automobile I get a distinct VIN variety than what my vehicle have and I can see that the bolts at the PCM were reduce, so the PCM has been modified at some stage. I even have already changed the o2 sensor, the crank attitude sensor without a achievement at all. Someone advised me that solenoid S7 inside the trans could be defective which controls the torque converter snatch, making it interact at random conditions, what could provide an explanation for the stalling and the no cranking. So I replaced the transmission, this made the automobile run exceptional for per week, but today it stalled again but I became capable of crank it right away. Please if a person have idea or facts approximately this I could extraordinarily recognize any assist.

[BarraT]

You will need to run Forscan 2.4, Run a KOEO and KOER Test, then check for fault codes and then data log items such as the 02 sensor to ensure it is switching, fuel trims, cam timing at idle, Check your power steering switch is operational, Check engine for air leaks using PID's IACTRIM & IACKAM3, Check fuel pressure and AFR, these are the basic starting points before changing parts

 

On 01/03/2024 at 9:01 PM, mc03 said:

I'm dealing with an issue on my 2003 BA turbo manual where the fuel pump relay is not getting a trigger signal from the PCM. The car is tuned with an SCT flash tuner, but this was done years ago, this issue is only recent. 

 

The fuel pump does not get a signal from the PCM to prime or run. Sometimes disconnecting the battery and letting the PCM reset will fix it, sometimes it won't, but eventually it stops working and won't work again until reset. 

 

The fuel pump and all its wiring after the fuse box is fine, the car runs without issue if I bridge out the fuel pump relay with a jumper wire. 

 

I have swapped and tested multiple relays and changed the inertia switch, didn't fix it.

 

The wires between the PCM and the fuel pump relay are fine (<1ohm), and all the PCM pins and connectors look fine, so I'm convinced the PCM isn't opening the ground signal to open the fuel pump relay (it does have 12v on the coil side). 

 

When it happens it throws code P0230 fuel pump relay primary circuit malfinction. 

 

Has anyone encountered this before and has any idea where to look next? Is my PCM dead?

 

Any advice is appreciated, thanks

If it runs fine with a jumper wire then the problem should be the relay / relays your using !

Please post your solution !

Edited 04/04/24 09:27 PM by BarraT

[mc03]

Thanks for these suggestions, however the issue is that the car won't even start. I will run the KOEO tests though when it happens next.

I don't think its the relay. I have tested and swapped multiple relays and know they are ok. When the issue occurs, the relay is not getting the ground signal from the PCM to open. I have confirmed this with a multimeter. Its either the PCM itself, or some other fault that is causing a fuel pump lockout in the PCM.

[Tom Tucker]

It's not uncommon for PCMs to fail in these cars as they age

[BarraT]

Have you pulled the Pump ? It could be shorting out

 

Trace all the wiring back and check the connections at the pcm

Check the fuse holder pins and the wiring under the relay box in the engine bay

Check all the fuses under the dash

 

 

[TobyXR6]

I have a 2002 XR6T manual with exactly the same problem that I have been chasing for half a year now. The car is totally stock (no flash tunes) and has been maintained very fastidiously since I bought it 19 years ago.

 

The symptoms are that the fuel pump relay cuts out and then, the starter relay won't allow the engine to crank. It happens when the engine gets hot (it can occur after a short while in warm driving conditions, or after a short drive and stopping for a while - and heat soaking occurring) both the fuel pump and starter relays won't work.

 

I have done significant testing to get to the "cause" of these relays not working including making a circuit board up with LEDs to monitor the voltages at each pin on both relays. I've traced the problem to the PCM not pulling the B27 FP pin (926) and EEC B (324) pin (for the fuel pump relay and starter relay respectively) to ground.

 

These relays require the PCM to ground the negative pin on their coil to allow the PCM to turn them off (e.g. to turn off the fuel pump if the engine stalls). I have even run my diagnostics wires to the connector at the PCM to be sure the issue is not in the wiring loom as my diagnostics also includes two over-ride switches that I can switch to provide an alternate ground (instead of the PCM) and therefore allow the car to run when the fault occurs. When I use these override switches, the fuel pump and starter relays work fine (though obviously this is not safe to do as the fuel pump will continue to run if the engine stalls - say after a big accident - but this is just to diagnose the issue).

 

I have sent the PCM, BCM and key to Injectronics for testing on their test rig and although the issue was still pretty intermittent the first time I sent it (it now is very consistent) and yet both times, they can't replicate the fault. I have faith in their testing and can only conclude that something (an input to the PCM) is causing it to turn both these relays off for some reason. As I said above, the fault occurs with heat (Injectronics tested it with heat and cold conditions, visually inspected the board for dry solder joints, cracks in tracks and blown ICs).

 

I have seen the familiar DTC code (P0230) occur but to be honest, I need to do some more testing and reading of the Ford manual.

 

I did wonder if it could be the crank sensor but I wouldn't expect that it would stop the starter output on the PCM from working (and you'd think it would also make it run pretty rough). I then wondered if it was something to do with the security system but when problem first occurs, the relay flickers (for a couple of seconds) before it cuts out (so its unlikely that the security system would trigger - via CAN - a flickering engine cut coms signal). Also (according to the Ford Manual), the security system also cuts ignition, so it can't be that as my "over-ride" switches allow the engine to run fine (when the fault occurs).

 

I think I need to do some more testing (and reading of the Ford Manual) but I think my issue is very similar to yours and probably due to the same cause.

 

20240410-FordPcmFaultDiagnosticLedWiring.pdf

[BarraT]

I have dealt with this issue in the past

 

The relay shuts down due to a short circuit to ground

 

Pull the pump, inspect / diagnose and if necessary replace

.....

Edited 24/04/24 09:36 PM by BarraT

[TobyXR6]

Thanks Barra T, I'll do some testing/diagnostics when I get my PCM back and the cars running again. While the PCM was sent away, I took the chance to get around to replacing the Diff Mounts so I've taken out the IRS module (and I'm also replacing all the rear suspension bushes to freshen it up while the IRS module is out - even though they don't look bad at all) so it might be a little while to I can do anything.

 

I'm not sure if the P0230 DTC is being set by my "over ride" grounding switch rather than from the actual fault. To enable the fuel pump to run when the fault occurs, I've wired in a "over ride" grounding

switch in parallel with the PCM's grounding output. As you earlier pointed out (though the manual is a bit unclear about this), the P0230 error detects a fault in the "primary FP circuit" but under the heading of "Electrical Condition" it suggests (as you found) to check for a short between the relay and the pump (secondary circuit of the relay...). Since the PCM is only controlling (and presumably sensing its voltage) the relay coil's ground pin, I can't see how it can determine a short (or open circuit) in the secondary circuit (between the relay and the pump).

 

But hey, I'm running out of ideas and there's nothing like getting input from someone who's had to deal with a similar problem, so thanks VERY much.

 

The thing that worries me (about assuming it's the fuel pump) is that it runs fine when I use my over-ride switch but maybe it intermittently shorts (or open circuits) and then the PCM detects it (somehow) and then via the P0230 diagnostic fault shuts it down or something. After all, fuel pumps fail... Either that or I'm causing the P0230 fault (while trying to fix some other cause) and sending myself on a wild goose chase.

 

Thanks again, your input is much appreciated.

 

 

[FGboy]

Currently experiencing the same thing on my FG turbo atm. Will casually start up after disconnecting battery and run fin, but once you turn it off and and leave it for about 10 minutes the fuel cut off switch kicks in, currently have the P0230 code as well 

 

Anyone got some ideas??