P0263

Diagnostic Chart:

Component Location:

CIRCUIT DESCRIPTION
The PCM has the ability to increase and decrease the amount of fuel to each cylinder in order to provide for a smooth idle operation. If the fuel correction amount exceeds the define limits, DTC P0263 will set. This is a type D DTC.

CONDITIONS FOR SETTING THE DTC
^ The engine is at idle.
^ The engine coolant is at the normal temperatures.
^ The cylinder fault must be constant.
^ The fuel correction amount exceeds the limits (internal to PCM).
^ The conditions were met for 2 seconds.

ACTION TAKEN WHEN THE DTC SETS
A possible rough idle.

CONDITIONS FOR CLEARING THE MIL/DTC
^ A History DTC will clear after forty consecutive warm-up cycles during which the diagnostic does not fail (the coolant temperature has risen 5°C (40°F) from the start up coolant temperature and the engine coolant temperature exceeds 71°C (160°F) during that same ignition cycle).
^ Use of a Scan tool will clear the DTC codes.

DIAGNOSTIC AIDS
The injector balance test on the scan tool should be used in order to confirm the cylinder problems. The Scan Tool will cutout the specific cylinder requested. If the original complaint was multiple cylinder balance DTCs and the vehicle has a manual transmission, a dual mass flywheel could be at fault. If a cylinder balance fault has been detected and the engine has been running for a long time, the PCM might try to increase or decrease the fuel in the other cylinders in order to compensate for a rough idle which may cause multiple cylinder balance DTCs to set. The scan tool snap shot mode can be used to properly identify the suspected cylinder. The most likely cause of cylinder balance DTCs are malfunctioning nozzles or any engine mechanical (low compression) problems.

TEST DESCRIPTION
The number(s) below refer to the Step number(s) on the Diagnostic Table.
2. This Step will properly identify a suspected cylinder by looking for an RPM drop (if the RPM drops, this indicates that the cylinder is contributing; if the RPM does not drop, this indicates that the cylinder is not contributing).