Problem: The owner brought the vehicle in
because the MIL was on and the engine was running rough.
Details: The technician installed a scan tool
and found a P0300 (multiple cylinder misfire) DTC. With his
scanner, he tried to read misfire data and could not. The
Tech-Assist consultant advised him to go to Mode 06 (In generic
OBDII) and check the misfire count. In Mode 06, he was able to
see a high incidence of misfires on all cylinders.
Confirmed Repair: After cleaning grounds F33
and F34, he retested the voltage drops and they were within
specifications. He cleared the DTC and road tested the vehicle.
The engine ran smooth and the misfire problem was fixed.