Cayenne Base (6 cylinder) Fault P12A2

1. SCAN TOOL: Scan DME for faults.

1. SCAN TOOL: Check DFI SET-POINT and ACTUAL high pressure circuit pressures in actual values (35000.00 mbar).

1. SCAN TOOL: Check MAF READINGS (Mass air flow) sensor. Engine OFF and Key ON, MAF Signal voltage not to exceed 1.2 Volts.

1. SCAN TOOL and MANOMETER: Fuel trim values and check crankcase breather readings for faulty AOS (RKAT 0% and FRA 0% and 5.0 – 6.0” H2O).

1. SMOKE TEST: IF fuel trim values are off.

1. FUEL PRESSURE: Check low pressure circuit fuel auxiliary fuel pressure gauge at fire wall.

1. FUEL INJECTION CLEANING (BG KIT): IF nothing has been found at this point, perform fuel injection cleaning (This might buy you some time).

1. CAMSHAFT TIMING: IF client wants to go farther, remove intake manifold and valve cover to check camshaft timing.

1. FUEL INJECTORS: IF no problems have been found at this point, replace all fuel injectors.

POSSIBLE ISSUES:

1. Fuel trim issue (Not necessarily faults).
2. Anything that can throw fuel air mixture off (MAF).
3. ANY vacuum and or air leaks.
4. Low Side fuel delivery issue.
5. Stretched timing chain (DFI HPFP timing off).
6. HPFP Fuel rail pressure too high or too low.
7. Injectors not flowing enough after cleaning – replace.