DTC 33

DTC 33 EGR Control Pressure/Baro Sensor Circuit High (Low Vacuum):

CIRCUIT DESCRIPTION
A Exhaust Gas Recirculation (EGR) control pressure/BARO sensor is used to monitor the amount of vacuum in the EGR circuit. It senses the actual vacuum in the FUR vacuum line and sends a signal hack to the Powertrain Control Module (PCM). This signal is used to control EGR duty cycle calculated by the PCM.

DIAGNOSTIC TROUBLE CODE (DTC) 33 WILL SET WHEN
^ EGR vent "OFF."
^ Desired EGR is less than or equal to 60 kPa.
^ EGR pressure is greater than 101 kPa.

ACTION TAKEN (PCM will default to)
PCM will shut "OFF" EGR system.

DTC 33 WILL CLEAR WHEN
The fault condition(s) no longer exist, and the ignition switch is cycled "OFF" then "ON."

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This step determines if DTC 33 is a hard failure or an intermittent condition.
2. This step simulates conditions for a DTC 31. If the PCM recognizes the change, the PCM and CKT 433 and CKT 416 are OK.

DIAGNOSTIC AIDS
With the ignition "ON' and the engine stopped, the manifold pressure is equal to atmospheric pressure with the signal voltage being high. This information is used by the PCM as an indicator of vehicle altitude.
Comparison of the reading with a known good vehicle with the same sensor is a good way to check accuracy of a "suspect" sensor Readings should be the same ± 0.4 volt.
A DTC 33 will result if CKT 452 is open or if CKT 433 is shorted to voltage or to CKT 416.
If DTC 33 is intermittent, refer to Intermittents. - Intermittent Malfunctions

NOTE: Make sure electrical connector remains securely fastened.

^ Refer to EGR Control Pressure/BARO Sensor Output Check for further diagnosis. EGR Control Pressure/BARO Sensor Output Check