MC Mondeo 2012 - electrical woes

[alpineraven]

Hey guys, hoping someone could help me to point me out to right direction - Apologies for long message;

Mk4.5 Mondeo 2012 – 2.0 TDCI 6spd Powershift.
Has rebuilt Powershift transmission, re-programmed ECM/ECU – full system flash by Ford, convers has been updated to latest etc (I know that the BCM/or PCM whatever has been replaced and I am suspicious its 2nd hand one – that mechanic who did it, isn’t communicative with me after we had a blow) Battery has been replaced (as was suggested to replace when it was playing up but ruled it out) and appears to be correct in IDS.

I have been getting random faults, each time it goes to Ford – they faults are cleared and or they haven’t found anything (they said they saw irreverent faults hence sensitive faults) Ford has done road tests 3 times for hours now etc trying to make a fault to appear, it doesn’t. (The Mondeo has been to Ford 4 times now, the first 2 times I’ve had to pay Ford to fault find for nothing as no faults were found, after 3rd time I haven’t paid Ford because I was complaining) – At early stage Ford did say you need to rebuild the transmission again until we realised its intermittent faults somewhere that the transmission is okay. (that is why I invested OBDII reader etc)

The fault appears randomly – out of blue/no-where. Could be days that it’ll be running perfectly then out of blue it’ll play up. And or if I am driving as normal “Limited Transmission Malfunction” message comes up out of blue – detected either P0715 or P0846 (see below) – turn key off then back on its all normal again.
There is two things that is playing up (see below) . And on the top of that, I could be a hour or more away from Ford and I am not driving while in Limp mode to Ford.

I noticed its more likely to occur in heavy traffic the transmission misses gears/doesn’t get in gear then slams into gear/or when downshift it’ll rev up. On warm day – 28°C outside, it was playing up just like if you’re in heavy traffic. ---> which leads me to think – temperature related causing PowerShift to play up and cause faults? Once pulled over – clear codes and turn key off/on then its all normal again!?

At night time, when I am driving, the headlight flicks off/on even convers will go from dim to bright then back to dim for a second, less than 2 seconds, no more than that – happens randomly – more likely to happen going around corners or speed hump – which leads to me to think loose connection somewhere to or from BCM which also causes faults above? Ive even thought crank angle sensor but it would throw up Engine Malfunction wouldn’t it?

I have been connecting to ForScan and I am getting random codes which I've been recording how many times (others aren’t recorded as its random irreverent codes), but the common ones, they are blow;

• P0715 Turbine/Input Shaft Speed Sensor A circuit (common one that pops up)
• U0126 – Lost communication with SASM (also another common one that also pops up)
• U0140 – Lost communication with BCM (also common that pops up but not all times – find it hard to clear that one up after a few DCT clears then It’ll be cleared)
• B1130 – Light switch module – Missing Message
• U0010 – Medium Speed CAN Communication Bus – Bus off
• P0846 – Transmission Fluid Pressure Sensor/Switch B Circuit Range/Performance (happened twice now)


Hope someone could help to point?

Cheers

AP

[cobrin]

you more than likely have multiple issues or that P0715 error playing up with the PCM thus giving off the some or rest of the errors. I can't tell you what/where the problem lies but I'd be looking at symptoms/causes and repairs you'd take and applying them to yours given that you'd be thinking are any two or more flags affect another.

P0715 may be the problematic speed sensor in the trans - Lokk for Bundybears thread on his results.

Look at the causes/repair procedures for more info:
U0126
U0140
B1130
U0010
P0846

Ground/earth points, connections corrosion look like possibilities along withcontrol modules and that speed sensor.