LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Suzuki >> 2006 >> Forenza Premium, 4D Sedan, Automatic >> Repair and Diagnosis (Single Page) >> Engine Performance >> Engine Control Systems >> Engine Performance - DTC P0401 - P0507 >> DTC P042E: Exhaust Gas Recirculation (EGR) Closed Position Performance >> Test Description
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

  1. The On-Board Diagnostic (OBD II) System Check prompts the technician to complete some basic checks and to store the Freeze Frame and Failure Records data on the scan tool if applicable. This creates an electronic copy of the data taken when the malfunction occurred. The information is then stored on the scan tool for later reference.
  2. Commanding the EGR valve open determines whether the EGR system can control the EGR valve accurately and if the fault is present.
  3. When the EGR valve electrical connector is disconnected, the scan tool should display the Actual EGR Position as 0%. If it does not, the fault lies either in the EGR signal circuit or the ECM.
  4. If the ERG valve 5 volt reference is shorted to voltage, the Digital Voltmeter (DVM) will read battery voltage and additional DTCs may be set and engine performance will be poor.
  5. The replacement ECM must be reprogrammed.

    Refer to the latest Techline procedure for ECM reprogramming.

  6. An open or poor connection condition may have caused this DTC to set. Be sure to check the terminals for being backed out, improperly formed or damaged, and for poor tension.
  7. All circuits to the EGR valve are OK at this point.

    The fault lies internally in the EGR valve and therefore must be replaced. Be sure all gasket material is removed from the EGR mounting surface. Even a small amount of material may cause a DTC P0401 to set.

  8. Check the terminals for being backed out, improperly formed or damaged, and for poor tension.
  9. Clearing DTCs is a very important step for this diagnostic. The clearing function allows the EGR valve to relearn a new pintle position as the old pintle position was inaccurate due to the failure that caused the DTC. The DTC must be cleared with the ignition ON, engine OFF or when the engine is idling. If the ECM sees an EGR command, the new pintle will not be learned.
  10. If no malfunctions have been found at this point and no additional DTCs were set, refer to Diagnostic Aids for additional checks and information.
scientia non olet · About LEMON Manuals