The Zener Diode Trick

If you’ve a Transit, for example a MK6 (2000.5 -2006.5 )& have raised boost via adjusting the wastegate, or have fitted a bigger turbo & have a model that has a boost ( MAP) sensor mounted on the intercooler as opposed to bulkhead mounted one, you’ll have found out that the limiter in the ECU program itself isn’t known ( cant be raised ) so one option is to fit a zener ziode on the boost sensor circuit to limit what boost the ECU actually see’s. Its a trick, & a good one at that. (If you’ve a bulkhead mounted boost sensor try disconnecting the silicon pipe that feeds it – that works fine on some ECU software versions & results in no boost on others

The theory is this – the zener diode rejects any voltage level up to the desired amount & bleeds off to ground any excess voltage. Let’s say on idle the return signal voltage is 2V, & at max boost before Ecu starts limiting is 4.4V, with a 4.4V zener in circuit any excess voltage between 4.4V & 5V is fed to ground so the Ecu only sees a max of 4.4V so fuel isn’t limited when boost exceeds original max & boost & consequently fuel quantity continues to rise. Without the zener diode fitted , the higher boost will mean higher voltage on the signal return wire than the ECU program allows & fuelling will be reduced ( in order to reduce boost to an “acceptable” level ) & you’ll get a subtle limp mode, negating any gains. 
Many MK6 have a 3 wire MAP ( boost) sensor-

Signal In (5V)

Signal Return (0-5V,  peaking towards 5V at max boost) 

Some MK6 have a 4 wire sensor, so is a TMAP not MAP sensor, the added T meaning temperature

One pin will be “NTC” , this is the thermistor output, for temperature reading. On some Bosch sensors its pin 2 , if you connect a multimeter probe to each pin in turn & other probe to ground, you can work out with engine running which is temp & which is boost by revving it up. A common pinut is as follows but verify yours to be sure

Pin 1 : Sensor Ground

Pin 2 : Temperature Signal “NTC”

Pin 3 : +5v in

Pin 4 : Map Signal Return

Try a 4.3V 1/4W or 4.7V 1/4W / 1/2 w or 1w Zener or measure the voltage at which once breached, the ECU cuts the fuel, then choose a zener of a value that has a breakdown voltage at that level to try as a starting point. Searching for zener diodes can be overwhelming as are the are 1000’s but search for this or similar “300pcs 30 Values (2V~39V) 1/2W 0.5W Assorted Zener Diodes Assortment Kit” (ebay link) & you ‘ll see you can get assortments with common useful values. You might find you need a 4.8V zener & you ‘l have to buy that separately as in reality the effectiveness of the circuit hack isn’t so clear cut, & a foolproof zener circuit includes a resistor to limit current , making the “breakdown voltage” more accurate & consistent but for simplicity, in most cases , just a zener alone will work . You’re attempting to limit a voltage range of between 4-5V so get some in that range ( EG: 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9) & experiment. Its much easier than you think , once you have some measurements & tests done.  If you buy an assortment of zeners & see them labelled as 4V6, thats a 4.6volt type.

Zener Diode

The side with the line on the zener needs to be connected to Signal Return & the other to the Ground wire.

This page has a more detailed explanation of the zener trick

Let me know your results & comments by posting below & i’ll update the post for more model specific details.

Transit MK8 Tipper 170ps 2019/2020 65mph Speed Limiter Removal

( Feb 2022 Update – it’s now cracked – the limit can be removed & all 2019+ models engine power can be uprated to 185ps as well if needed.)

170ps Euro6d (6d-TEMP) Tippers that use the SID212evo engine ECU have a factory limiter set about 65mph, it’s due to what Ford call “Whole Life Testing Protocol” Recent emissions scandals really focused regulators on emissions after delivery is made & it’s calculated that in a year or 3 once engine & tyres are worn etc the emissions on affected models may just go over the prescribed limit. Normally one would hack the engine ECU to kill the limit but because no remapping equipment can access the Continental SID212/212evo engine ECU file yet it’s not yet possible. ( October 2020) “Diagnostically” it’s a no go even for those with online dealer tool access. I’m not 100% if it’s only 170’s but have heard 105ps models are not affected – You can check your ECU type – there is a label on it & its behind the passenger headlamp. If you’ve a SID211 it’s easy to remove any limiter & anything else is not.

Iveco Daily China Fuel Regulator Valve any good ?

Bogdan ( I love that name ) had me remove the immobiliser from his 2005 Euro 3 Daily. It still wouldn’t start. Fuel was getting to the high pressure pump on the engine but no further. He sourced a Chinese 45 Ebay valve & van ran but cut out under 1000rpm. He then sourced a £68 quid genuine one from Coastal Motorhomes & it ran perfectly. So buy Bosch from a good source as the fakes continue to flood the part market.

Part Number may be

CROSS REF NO: 71772310

Some handy Iveco Immobiliser & fuse info is held on this page:

MK6 Transit Tacho Removal

Essentially, to get the speedo to read your mileage again once tacho is physically removed , you need to source & fit a bypass loom, available from Henry Ford himself. The part number is 3C1T-10B942-AA & the “finis”code is 4522300. Is the part still available ? if not , just 2 connectors appear to be linked in the grey tacho plug (yellow & white with purple tracer).

Euro 5 MK7 Transit Overboost

Had a 2012 100ps FWD MK7 in, that would hit 2.6 Bar boost, then go into limp mode, then push the gas twice & its Ok again for a minute. No DTC’s were set. To cut a long & very boring story short, the new turbo was actually recon & the dowel that locates the VNT mechanism into the turbine body was missing & it was mis-aligned. a part of a broken 3.5mm drill bill stepped in a dowel & all was good. Actuator wise, the G number was G32 & this was for a front wheel drive, i’m told the rear wheel drive actuators differ in the arm cam position or sweep., so possibly, a rear wheel drive utilises a different G number.

2000 Iveco Daily Immobiliser Removal

Its a manual process on these, as the full ECU controlled immobilser system was fitted from about 2002.

Hi Martyn

Thanks for your time and help with my 2000 Iveco 2.8.

The issue was resolved by removing the immobiliser and rewiring the stop solenoid.

I will put together some info but in case you get any other enquiries, a couple of quick points.

Removing the immobiliser is really easy with a Dremel tool, cutting disks and grinding head. Took only a few minutes.

The original power to the immobiliser can be utilised to provide power for the stop solenoid without adding a new switch/wire, and continues to work from the ignition.

Again, thanks

Nick Meacham

Cloning Service for Ford Transit & Transit Custom Body Control Modules

Vantuner now offers a while you wait or postal BCM cloning service on Ford Transit MK7’s , Euro 4 & 5 from 2006.5 to 2014. Send your faulty BCM along with a cheap used one & i’ll copy over all memories , making your new BCM plug & play. Additional key’s can be added also. Custom & MK8 can be cloned using used BCM’s also Commonly water gets into the upper plugs from leaks around the windscreen or roof rack mounts or bulkhead seams , or some circuits just fail like headlamps or wipers etc , . Call or WhatsApp me on 07956555666 for more info