Cylinder Balance Test: Description

The cylinder balance test is designed to aid in the detection of a non-contributing cylinder. The cylinder balance test first reads engine RPM, with all injectors activated. Next each injector is turned "off and on", one at a time. The RPM drop that results, if any, is then read. These two RPM's are compared to verify that the RPM drop was greater than a calibrated level.

The cylinder balance test has the capability of comparing RPM drop of each cylinder against three different calibrated levels. the first level checks for gross errors (electrical opens, shorts, etc). The second and third levels check for partially contributing cylinders. If the appropriate RPM drop is not achieved at any levels, then a service code corresponding to that cylinder will be set. For the cylinder balance test codes see SERVICE TEST CODE TABLE.