DTC 33

Code 33 Chart:

Code 33 Wiring Diagram:

CIRCUIT DESCRIPTION:


The manifold absolute pressure (MAP) sensor responds to changes in manifold pressure (vacuum). The ECM receives this information as a signal voltage that will vary from about 1 to 1.5 volts at idle, when manifold pressure is low (high vacuum), to 4.5 - 4.8 volts at wide open throttle (low vacuum or high pressure).

If the MAP sensor fails, the ECM will substitute a fixed MAP value and use the throttle position sensor (TPS) to control fuel delivery.


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. This step will determine if Code 33 is the result of a hard failure or an intermittent condition.

Code 33 will set when:

^ MAP sensor is greater than 80 kPa.
^ TPS less than 12%.
^ Above conditions met for longer than 5 seconds.

2. With the MAP sensor disconnected, the ECM terminal "GF15" voltage should be low if the ECM and wiring ok.

DIAGNOSTIC AIDS:


^ A code 33 will result if circuit 469 is open or if circuit 432 is shorted to voltage or to circuit 416.