HB1 - Check For Fuel Diluted Engine Oil

Cylinder Balance Test Chart:

NOTE: Diagnostic Trouble Codes (DTC) followed by a "c" indicate a continuous memory code while DTCs followed by an "r" indicate an on demand code.

Possible Causes:

- Fuel injectors.

- Plugged fuel filter.

- Fuel pump.

- Heated Oxygen Sensor (HO2S).

- Positive Crankcase Ventilation (PCV)/Hose.

- Vacuum.

- Evaporative canister purge.

- Electronic ignition coil failure.

- Key "OFF".

- Remove the PCV valve from the valve cover. Inspect both rocker cover hole and PCV for damage, sludge build up, blockage and movement of valve plunger. Service as necessary.

- Run Key On Engine Off (KOEO) and Key On Engine Running (KOER) Self-Tests. Quick Test Appendix (Detailed Testing Instructions)

- Address any continuous ignition DTCs before servicing KOER DTCs.

NOTE: For a No Start, go directly to HB2. HB2 - Check Fuel Pressure

- Are any of the above DTCs present in KOER Self-Test?

Yes -- Reinstall PCV valve. Go to HB2. HB2 - Check Fuel Pressure

No -- For Continuous Memory DTCs 139, 141, 144, 176 Go to HB2. HB2 - Check Fuel Pressure

All Others: Change engine oil and filter with flexible fuel grade oil. Reinstall PCV valve. Drive vehicle 5 miles/55 mph. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)