2012 FISTA SE P0068 INTERMITTENT

[FiEsTaTiMe]

HAS ANYONE COME ACROSS THIS CODE? IF SO WHAT WAS THE OUTCOME? SOLUTION(S)? THANK YOU

 

[Handy Andy]

P0068 - is a code that is set when the PCM, the engine - can't set mixture with the results it's getting from two sensors.

One, The Throttle Body Position - Sensor - The Throttle Body is electronic, so it receives a signal from the PCM to move a stepper motor to move the throttle plate, it "checks itself" by looking at a wiper arm over a resistive element inside the Electronics of the Throttle body (that black panel) - so it determines how much air is entering into the system and uses this to calculate mixture....Uses the Accelerator Pedal Position Sensor (throttle pedal) to help set angle.

Second - The MAF sensor - This sensor is also electronic - it compares air pressure - between the intake manifold vacuum pressure - inside it - and the outside air pressure - it also uses this sensor to calculate Mixture

• - since Engine load varies - this sensor looks at vacuum in the manifold as a "barometer" of things to come that it has to anticipate. When the engine is at idle - vacuum is high, and MAF tells the PCM this - so it can set the Throttle Plate "angle" to a tight close gap to throttle bore angle setting - keeping more air outside than inside - so it calculates mixture for that. When the engine starts to load down - the manifolds vacuum pressure drops (Sees it going back to same outside air pressure) - and so does the RPM (possible Stall moment) - so the system "thinks" it's having to add more throttle and some fuel mixture adjustment - so the system moves the throttle plate open away from the bores' closed position - allows more air - dropping vacuum even faster, but then it has to know "why?" and what is the Accelerator Pedal Position Sensor doing? Oh? Hmm - so the system will only let so much change occur before it seems there is something wrong and set a code - your P0068.

So that means you have a problem - with manifold vacuum leaks or the throttle body is dirty or even sticking - plugged - and you have to clean it out so the system can relearn mixture. This "dirt and gunk" can also affect the MAF sensor and plug it up - get coated with blowby and old oil and fumes and dirt in the manifold so it can't detect vacuum and respond correctly. This can also mean a bad or cracked hose allowing air in affecting the ability to calculate mixture in a closed setting.