Cylinder Balance Test
1) 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.
2) 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.
3) 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.
4) 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 is not displayed, cylinder is considered non-contributing.
| 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 |
| Symptom | Application | Circuit Test | ||
|---|---|---|---|---|
| A/C Does Not Cut Off During WOT | All Models | KM - Step 15) | ||
| A/C Not Functioning | All Models | KM - Step 1) | ||
| Black Exhaust Smoke | All Models | H - Step 1) | ||
| CHECK ENGINE Light Always On | All Models | ML - Step 1) | ||
| CHECK ENGINE Lt. Flashing With Erratic Idle | (1) All Models | ML - Step 15) | ||
| CHECK ENGINE Light Never On | (1) All Models | ML - Step 4) | ||
| CHECK ENGINE Light On Intermittently | (1) All Models | ML - Step 10) | ||
| Engine Hesitates After Hot Restart | (1) All Models | H - Step 21) | ||
| Engine Hesitation | (1) All Models | S - Step 2) | ||
| Engine Lacks Power Or Loses Power | (1) All Models | S - Step 2) | ||
| Engine Miss At Idle, Accel. Or Cruise | (1) All Models | S - Step 2) | ||
| Engine Runs Rough At All Times | (1) All Models | S - Step 2) | ||
| Engine Stalls | All Models | S - Step 2) | ||
| Engine Stalls During Trans. Downshift | Models With A/T | TC - Step 1) | ||
| Engine Stalls During Trans. Engagement | Models With A/T | TC - Step 1) | ||
| Engine Stalls When Parking | Models With PSP Switch | FF - Step 2) | ||
| Engine Surge At Accel. Or Cruise | (1) All Models | S - Step 2) | ||
| Erratic RPM | (1) All Models | S - Step 2) | ||
| Gasoline Fumes | Models With CANP | KD - Step 1) | ||
|
||||