With PFI

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 - 4.5 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) and other sensors to control fuel delivery.


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 intermittent condition.

^ MAP signal greater than 80 kPa..
^ TPS less than 12%.
^ VSS speed sensor.
^ The above conditions are met for a time longer than 5 seconds.

2. With the MAP sensor disconnected, the ECM terminal YF15 should be low if the ECM and wiring are ok.




DIAGNOSTIC AIDS:

A Code 33 will result if circuit 469 is open. If code 33 is intermittent, Refer to TESTING PROCEDURES/DIAGNOSIS BY SYMPTOM/INTERMITTENTS.