Vehicle

Ford Falcon, BA, 4.0l 6cyl, P light flashing after driving for a short period of time.

Symptom:

The vehicle would go into limp mode and the P or D light will flash, whilst driving the accelerator actuation is stuck in limp mode so 30 kmh is as fast as you can drive the vehicle.

Diagnostics:

The scan tool was used first of to test for fault codes

and as follows

• P0753 – 63, Shift Sol A Electrical.
• P0758 – 63, Shift Sol B Electrical.
• P0763 – 63, Shift Sol C Electrical.
• P0768 – 63, Shift Sol D Electrical.
• P1748 – 63 Electronic Pressure control circuit fault.
• there was also a throttle fault but we didn’t worry too much about this as when the vehicle was in limp this fault code was set.

Wiring diagram listed here Falcon BA_2003 auto harness wiring 

after looking at the wiring diagram, this showed that the only common link was the power to all the solenoids in the transmission, so the EEC power relay was changed for a new unit, the Pico scope was set to measure power circuit at the gearbox (red wire) for glitches, what this does instead of constantly running new pages it keeps a shadow of each reading so you can walk away and come back to see if the power dropped below 10 volts, not that it did, the only other thing to check was the grounds to the PCM just in case it was dropping out we ran a drop earth test and found it to be ok.

This lead to the PCM being faulty, 3R23-12a650-AH

This PCM/ECU was the part number we rang the wreckers and found a suitable second hand unit and programmed to the vehicle by gaining security access and carrying out a parameter reset. which enables the vehicle to start.

After this the radio did not work and the Radio Displayed ‘CODE’ to set the radio on these vehicles you must carry out a ACM calibration to make radio work.
then you can test drive.

The fun did not stop there, during the test drive we found that whilst driving at roughly 60 kmh the speedo would read 100kmh and vary, this was strange as it did not do this before.
so just to verify we reinstalled the old control module and took the vehicle for a test drive and confirmed that the Old ECU was ok in the speedometer circuits and the new / second hand PCM was faulty.
The only problem with this is that you have to wait 10 mins again to swap the Engine ECU’s in order to start the vehicle.

The IDS/VCM was again plugged in and the tyre size/axle ratio was checked with the old versus new PCM’s and no difference found so this confirms the new  second hand PCM is indeed faulty.

results where, 215/60R16 and axle ratio of 3.23
Wait till the morning and get another replacement.

But before we decided to throw in the towel we decided to check the programmable parameters – speed items and check the difference in calibration which could lead to the function being wrong

Original PCM.

• Speed control – (PCM) = Not present
• Speed Signal Output Control – (PCM) = Other.

Remembering what was different

Change the PCM’s once again (10min wait time) and carry out this check on the new/second hand PCM.

This time it was best to use Programmable Module installation rather that just the parameter reset function. (hoping this should utilise all the original functions and rewrite the Vin code to the new PCM, also by doing this the latest calibration files according to your VCM suite will update the original PCM and change it from 3R23-12a650-AH to 3R23-12a650-AL.

That was a bit of wishful thinking the immobiliser light is still on looks like a parameter reset will have to be done, at least all the configurations have been brought across and now a parameter reset can now ben done and the speedo should work correctly.

PCM Programming functions of the FORD

Paramater reset – relinks security and aligns bcm to pcm by the way of a hand shake.
PMI – Programmable Module Installation – copies data from old unit to new unit including Vin number if it is applicable to that module.

Side Note not many people can tell you the difference , suppose it up to a good technician to work out the differences in all different vehicle manufactures and create log of what you have done and refer to it when carrying out such a repair to a vehicle ( ahh the things I wish I knew when I was seventeen).

On a Similar note B2141 – NVM Configuration Failure

B2141 – NVM Configuration Failure, if you get this failure you are probably being a tight arse and not programming with 2 keys, i have tried programming with one key, you cant start the car and you get this fault code coming up after you have carried out programmable module installation, you need to cut your self (or get one cut) 4d62 transponder and program 2 keys dont think you are smarter than ford engineers that make you have 2 keys, this is part of the authority system that makes the job time longer, and harder to carry out, whilst on the road.

Summary:

the diagnostic time to work out that the PCM was faulty was 2.5 hours on and off with scope and scan tool work. programming the module took another 1.5 hours due to the differences in the programming. Writing all this down and remembering which way to do things whilst conducting the parameter resets.

in a full summary tedious time has been taken up working out how to reproduce the faults and setting up test gear to determine the PCM was faulty.

Images

BA Falcon, identity, ECU update complete with reprogramming into new vehicle complete.