P0272

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION
The Powertrain Control Module (PCM)) has the ability to increase and decrease the amount of fuel to each cylinder to provide smooth idle operation. If the fuel correction amount exceeds define limits, DTC P0272 will set. This is a type D DTC.

CONDITIONS FOR SETTING THE DTC
- Engine at idle.
- Engine coolant at normal temperatures.
- Cylinder fault must be constant.
- Fuel correction amount exceeds limits (internal to PCM).
- Conditions met for 2 seconds.

ACTION TAKEN WHEN THE DTC SETS
Possible rough idle

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

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

TEST DESCRIPTION
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 a RPM drop (if RPM drops, cylinder is contributing, if not cylinder is not contributing).