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.
| Service Code | Description |
|---|---|
| 10 | Cylinder No. 1 Problem |
| 20 | Cylinder No. 2 Problem |
| 30 | Cylinder No. 3 Problem |
| 40 | Cylinder No. 4 Problem |
| 50 | Cylinder No. 5 Problem |
| 60 | Cylinder No. 6 Problem |
| 70 | Cylinder No. 7 Problem |
| 77 (1) | Rerun Test |
| 80 | Cylinder No. 8 Problem |
| 90 | No Problems Encountered |
| (1) If throttle is touched (moved) during cylinder balance test, service code 77 will appear, indicating test was not completed. | |
| (1) | If throttle is touched (moved) during cylinder balance test, service code 77 will appear, indicating test was not completed. |
SERVICE TEST CODE
- Perform Engine Running Self-Test. See appropriate article in the ENGINE PERFORMANCE Section. After the last repeated service code is received, wait 5-10 seconds. Lightly depress and release throttle (not wide-open throttle) within the last two minutes of the last repeated service code.
- Cylinder balance test will be performed at the first test level. Test time is approximately three minutes.
- After the last cylinder balance test pass code 90, re-enter test within two minutes by lightly depressing and releasing the throttle. The second level of the Cylinder balance test will now be performed.
- After the last cylinder balance test pass code 90, re-enter test within two minutes by lightly depressing and releasing the throttle. Cylinder balance test will now be tested at the third test level.
- Cylinder balance test may be repeated as many times as necessary by repeating step 3). All additional testing will be performed at the third test level.
the cylinder balance test is designed to aid in the detection of non-contributing or partially contributing cylinder.