The EGR valve vacuum is controlled by an ECM operated solenoid. The ECM will turn the EGR "on" and "off" (Duty Cycle) by grounding CKT 901. The duty cycle is calculated by the ECM based on information from the coolant sensor, MAP sensor and engine rpm. There should be 0% (no EGR) when in Park or Neutral, TPS input below a specified value or TPS indicating Wide Open Throttle (WOT).
With the ignition on, engine stopped, the EGR solenoid is de-energized unless the diagonstic terminal is grounded.
Code 32 means that the EGR diagnostic switch was not detected closed under the following conditions:
A Scantool can be used to check the diagnostic switch circuit. The Scantool should display "on" when vacuum is applied to the diagnostic switch. The switch should also be indicated as being closed whenever the ECM is commanding an EGR duty cycle of greater than 50%. EGR duty cycle can also be monitored by a Scantool.
Before using this test, check for ported vacuum to EGR solenoid, also check hoses for leaks or restrictions. There should be at least 7"hg vacuum at 2000 rpm.
Disconnect EGR solenoid vacuum harness. Rotate harness and reinstall only the EGR valve side. Ignition on, engine stopped. Install a hand held vacuum pump with gauge to mainfold side of EGR solenoid. Apply vacuum and observe EGR valve, the valve should not move.