Diagnostic Aids

If MAP sensor is disconnected, ECM will go into back-up MAP mode. An open ground circuit will set a Code 33. If idle is rough or unstable, refer to SYMPTOMS in H - TESTING W/O CODES article in this section to help determine if idle problem is causing Code 33.

Fig 1: Code 33: MAP Sensor Volt Hi Ckt Diag (5.0L & 5.7L)

Fig 2: Code 33: MAP Sensor Volt Hi Flow Chart