Cylinder Balance Test
- This test helps identify a weak or non-contributing cylinder in engines with SFI fuel systems. PCM shuts off fuel supply to each injector and measures RPM drop. It computes variation between cylinders and identifies weak ones. Total test time is about 3 minutes.
- This test mode is entered from KOER SELF-TEST after all codes have been displayed. Within 2 minutes after codes have been displayed, apply and release throttle). After a brief stabilizing period, PCM will activate test procedure.
- If Code 90 is displayed during this test, system has passed test. If Code 77 is displayed, repeat cylinder balance test. If throttle is moved during this test, Code 77 will appear, indicating test is not completed. If a weak cylinder is indicated, repeat test. See CYLINDER BALANCE TEST SERVICE CODES table.
- Test will be repeated if throttle is applied and released within 2 minutes of final code output. When repeating test sequence, percentage of allowable variation between cylinders is reduced. If Code 90 is displayed, cylinder identified in previous first test is considered weak. If code 90 cannot be obtained, cylinder is considered non-contributing.
CYLINDER BALANCE TEST SERVICE CODES
| Service Code | Application |
|---|---|
| 90 | Pass |
| 10 | Cylinder No. 1 |
| 20 | Cylinder No. 2 |
| 30 | Cylinder No. 3 |
| 40 | Cylinder No. 4 |
| 50 | Cylinder No. 5 |
| 60 | Cylinder No. 6 |
| 70 | Cylinder No. 7 |
| 80 | Cylinder No. 8 |
| 77 | Retest |