H6 - Cylinder Balance Diagnostic Test Mode: SFI Engines

Cylinder Balance Test Chart:

The cylinder balance diagnostic test switches each injector OFF and ON one at a time. Diagnostic Trouble Codes (DTC) correspond to the cylinder number (i.e., Service DTC 30 indicates a problem with cylinder No. 3, a DTC 90 indicates a pass.) The cylinder balance test is designed to aid in the detection of a weak or non-contributing cylinder. The pinpoint test steps are designed to isolate only Electronic Engine Controls (EEC) related problems.

NOTE: If throttle is touched (moved) during the cylinder balance test, DTC 538 will appear, indicating test was not completed. DTC 538 could also be output if a continuous memory DTC 214 is present. If DTC 214 is present proceed with diagnosising DTC 214 prior to running the cylinder balance test.


- Run the Key On Engine Running (KOER) Self-Test. Key ON Engine Running (KOER) Self-Test

- After the last repeated code, wait 5-10 seconds.

- "Goose" throttle lightly (not wide-open-throttle).

- Cylinder balance test will be performed. Time of test is approximately 2-3 minutes.

- Are there any cylinder balance DTCs requiring service?

Yes -- Go to H8. H8 - Check Resistance of Injector(s) and Harness SFI Engines

No -- For Symptoms: Return to Diagnostic Routines.

For DTC 136, 172, 176: Go to H13. H13 - Check Secondary Air Injection Operation

For DTC 137, 173, 177: Go to H24. H24 - Check HO2S Signal For Short to Power

For all others: Go to H14. H14 - Check HO2S Integrity