DTC 33

Code 33 Chart:

Code 33 Wiring Diagram:

CIRCUIT DESCRIPTION:

The manifold absolute pressure sensor (MAP) responds to changes in vacuum (manifold pressure). The ECM receives this information as a voltage that varies from about 1 to 1.5 volts at idle (high vacuum) to 4-4.5 volts at wide open throttle (low vacuum).

NOTE: Because of all the possible color code combinations used on electrical wiring diagrams, always refer to ECM CONNECTOR IDENTIFICATION under ELECTRICAL AND ELECTRONIC WIRING DIAGRAMS for correct color code identification of circuit.

TEST DESCRIPTION: Numbers below refer to circled numbers on the diagnostic chart.

1. Code 33 will set if:

^ Engine is running.
^ Manifold pressure is more than 74 kPa with A/C off or 83.4 kPa with A/C on.
^ Throttle angle is less than 2%.
^ Conditions are met for 4.8 seconds.
^ Engine misfire or a low unstable idle may set a code 33.

2. With MAP disconnected the ECM should see a low voltage if the ECM and wiring are good.

DIAGNOSTIC AIDS:


^ An open in CKT 455 or connections will set a code 33.

^ Ignition "ON", engine "OFF", voltages should be within the values shown in the table on the chart. Also CHART C-1D can be used to test the MAP sensor.

^ If idle is Rough unstable or incorrect. Refer to TESTING PROCEDURES/DIAGNOSIS BY SYMPTOM/INTERMITTENTS.