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Home >> GMC >> 1999 >> Forward Control 4.3 W, Automatic >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Controls Tests W/Codes - Diesel >> Diagnostic Tests >> DTC P0604: Control Module Random Access Memory ("C", "G" & "K" Series) >> Diagnostic Procedures
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Diagnostic Procedures

  1. If OBD system check has been performed, go to next step. If OBD system check has not been performed, go to ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM.
  2. Replace PCM. Program PCM using required equipment. After replacing PCM, go to next step.
  3. Using scan tool, select DTC, CLEAR INFO. Start and warm engine to normal operating temperature. Select DTC, SPECIFIC, and then enter DTC P0604. Operate vehicle within the conditions for setting this DTC. If scan tool indicates that this test ran and passed, go to next step. If scan tool does not indicate that this test ran and passed, repeat step  2.
  4. Using scan tool, select CAPTURE INFO, REVIEW INFO. If any undiagnosed DTC(s) are displayed, go to applicable DTC test.
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