DC21 - Rerun Self-Test W/MAF Sensor Disconnected

Diagnostic Trouble Code (DTC) 158 indicates the Mass Air Flow (MAF) sensor signal went above 4.5 volts during normal engine operation (continuous) or during Self-Test.

NOTE: DTC 158 could be generated by foreign material blocking the Mass Air Flow sensor screen creating an air flow restriction. If contaminants are found on the screen, check air filter installation in air cleaner tray and proper sealing of air cleaner/tube before proceeding.

- Key "OFF".

- Disconnect MAF sensor.

- Start engine, idle one minute.

- Key "OFF".

- Run Key On Engine Off Self-Test. Quick Test Appendix (Detailed Testing Instructions)

- Is DTC 157 present?

Yes -- Replace MAF sensor. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)

No -- Go to DC22. DC22 - Check MAF Circuit For Short to VPWR