P0275

DTC P0275 Cylinder 5 Balance System






Circuit Description

The PCM has the ability to increase and decrease the amount of the fuel to each cylinder in order to provide for a smooth idle operation. If the fuel correction amount exceeds the defined limits, DTC P0275 will set.

Conditions for Running the DTC

^ The engine is at idle.
^ The engine coolant is at the normal temperatures.
^ The cylinder fault must be constant.

Conditions for Setting the DTC

^ The fuel correction amount exceeds the limits (internal to PCM).
^ All diagnostic set conditions met for 2 seconds.

Action Taken When the DTC Sets

^ The PCM will not illuminate the Malfunction Indicator Lamp (MIL).
^ The PCM records the operating conditions at the time the diagnostic fails. This information is stored in the Failure Record.

Conditions for Clearing the MIL/DTC

^ A History DTC will clear after forty consecutive warm-up cycles, if this or any other emission related diagnostic does not report any failures.
^ 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 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 will 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 in order to properly identify the suspected cylinder. The most likely cause of cylinder balance DTCs are malfunctioning nozzles or engine mechanical (low compression) problems.

If multiple cylinder balance DTCs are set and no problem is found, check for the following:

^ Pinched or restricted fuel feed lines between the fuel tank and the fuel injection pump
^ Restricted fuel filter
^ Fuel waxing

A fuel system restriction could cause the fuel correction to exceed the limits.

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).