Tech Tips (by ALLDATA): F350 runs rough – multiple DTCs

TECH TIPS (courtesy of ALLDATA)

Vehicle: 2011 Ford F350 Super Duty, 2WD, 6.7L Turbo Diesel, Automatic Transmission

Mileage: 78,009

Problem: The vehicle came into the shop running rough and the MIL was on.

Details: The technician connected a scan tool and retrieved the following DTCs: P0201 – Injector Circuit/Open – Cylinder 1 / P0202 – Injector Circuit/Open – Cylinder 2 / P1201 – Cylinder 1 Injector Circuit Open/Shorted / P1202 – Cylinder 2 Injector Circuit Open/Shorted. Based on those diagnostic trouble codes, the tech performed a resistance test on the injectors.

The best way to test the entire circuit from the PCM to the injectors, was to take the readings from the PCM connector C1232E through the injectors (see image). The resistance should be between 150K to 210K ohms.

Confirmed Repair: The injector resistance test revealed that the resistance in the #1 and #2 injector circuits was fluctuating between OL and 160K Ohms. The other injectors were steady at 170K Ohms. The technician replaced the #1 and #2 injectors. On the test drive, the engine ran smooth and the DTCs did not return.