GM Malibu/Cutlass 1997-2000

Exhaust Gas Recirculation System

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OPERATION





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Fig. Cut-away view of the linear EGR valve

The vehicles covered by this guide are equipped with a linear Exhaust Gas Recirculation (EGR) valve. The linear EGR valve is designed to accurately apply EGR to an engine, independent of intake manifold vacuum. The valve controls EGR flow from the exhaust to the intake manifold through an orifice with a PCM controlled pintle. During operation, the PCM controls pintle position by monitoring the pintle position feedback signal. The PCM uses information from the Engine Coolant Temperature (ECT) sensor, Throttle Position (TP) sensor and the Mass Air Flow (MAF) sensor to determine the appropriate rate of flow for a particular engine operating condition.

TESTING



The PCM tests the EGR system for system flow during acceleration momentarily commanding the EGR valve to open while monitoring the Manifold Absolute Pressure (MAP) sensor signal. If the results are out of the programmed range, the PCM will eventually set a Diagnostic Trouble Code (DTC). Refer to the procedures for pulling and reading DTCs later in this section.

The PCM also monitors the valve pintle position input to ensure the valve responds properly to commands from the PCM. If the PCM sees a fault in the circuit it will then set a DTC. Refer to the procedures for pulling and reading DTCs later in this section.

A test for the 3.1L engine's EGR valve control coil is easily accomplished with a Digital Multi-Meter (DMM), as follows:

  1. Detach the EGR valve electrical connector.
  2.  
  3. With a DMM set to the ohms scale, probe the valves connector at terminals A and E . A diagram of the terminals should be located on the top of the valve directly above the connector. Connector terminals start with A on the left-most terminal and progress down the alphabet.
  4.  
  5. The DMM should read between 9.5 to 10.5 ohms resistance on a hot engine, maybe as low as 7 ohms on a cold engine. If this is out of range, the coil in the EGR will not operate properly and should be replaced.
  6.  



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Fig. The EGR control coil's resistance should be between approximately 7 to 10 ohms

REMOVAL & INSTALLATION





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Fig. The EGR valve (2) on the 2.4L engine is mounted with a gasket (3) on the front of the engine and secured with 2 bolts (1)



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Fig. Remove the EGR valve mounting bolts, remove the valve . . .



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Fig. . . . then remove the gasket and thoroughly clean the EGR mounting surface

  1. On the 2.4L engine, remove the air cleaner outlet resonator.
  2.  
  3. Detach the electrical connector from the EGR valve.
  4.  
  5. Remove the EGR valve mounting bolts, then remove the EGR valve.
  6.  
  7. Remove and discard the gasket.
  8.  

To install:


NOTE
Be sure to thoroughly clean the EGR mounting surface. Even a small amount of gasket material or debris may cause a DTC to set.

  1. With a gasket scraper or putty knife, thoroughly clean the old gasket material off the valve mounting surface.
  2.  
  3. Install the EGR valve with a new gasket.
  4.  
  5. Install the mounting bolts and tighten to 22 ft. lbs. (30 Nm).
  6.  
  7. Attach the EGR valve electrical connector.
  8.  
  9. On the 2.4L engine, install the air cleaner outlet resonator.
  10.  

 
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