DTC 32

DTC 32 Circuit Diagram:

DTC 32 Diagnostic Chart EGR System:

CIRCUIT DESCRIPTION:

The EGR vacuum valve is controlled by an ECM controlled solenoid. The ECM will turn the EGR "ON" and "OFF (Duty Cycle) by grounding WHT/GRN wire. The duty cycle is calculated by the ECM, based on information from the coolant temperature sensor and the throttle position sensor. With the ignition ON and the engine stopped, the EGR solenoid is de-energized and by grounding the diagnostic terminal, the solenoid is energized.

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

1. Code 32 will set if the following conditions exist:
^ Engine at normal temperature.
^ Temperature difference less than 3° C when EGR is commanded "ON" and "OFF".
^ Or signal voltage indicates an EGR gas temperature above 350° C or below -36° C.

2. This test determines if the EGR gas temperature sensor or the EGR valve is at fault or if the ECM and/or wiring are at fault.

DIAGNOSTIC AIDS:

A scan tool reads EGR gas temperature in degrees celsius. After the engine is started, the temperature should nearly reach manifold temperature, when the EGR is OFF. When the EGR is ON, temperature should be between 100° C and 250° C.