DTC 33

Fig. 008 - Wiring Diagram for Code 33 MAP Sensor Signal Voltage Too High):

CODE 33, MAP SENSOR (SIGNAL VOLTAGE HIGH)

The Manifold Absolute Pressure sensor (MAP) responds to changes in manifold pressure (vacuum). The ECM receives this information as a signal voltage that will vary from about 1 to 1-1/2 volts at idle to 4-4.5 volts at wide open throttle.
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 33 will set when:
a. Signal is too high for a time greater than 8 seconds;
b. TPS voltage indicates throttle is closed; and
c. Vehicle is stopped (no VSS signal).
d. A very low and unstable idle may set a Code 33. Correct this condition before using Code 33 Chart.

Fig. 007 - Chart Code 33 MAP Sensor (Signal Voltage Too High):

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