DTC 34

The Manifold Absolute Pressure Sensor (MAP) responds to changes in manifold pressure and vacuum. The ECM receives this information as a signal voltage that will vary from about 1 to 1.5 volts at idle to 4 to 4.5 volts at wide open throttle (WOT).

If the MAP sensor fails the ECM will substitute a fixed MAP value and use the Throttle Position Sensor (TPS) to control fuel delivery.

Code 34 will set when the signal voltage is too low and the ignition is "ON".

1. Confirms Code 34 and that fault is present.
2. If the ECM recognizes and sets Code 33, high MAP signal, the ECM and wiring are OK.