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Diagnostic Procedures

WARNING: This page is about a different car, the 2003 Mazda B4000, 2003 Mazda B3000, and 2003 Mazda B2300. However, it is still accessible from the selected car via links, so may be relevant.
  1. If QUICK TEST was not performed, go to QUICK TEST  under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed:
    • For KOEO or KOER DTC P1409, go to next step.
    • For Continuous Memory DTC P1409, go to step  7 .
  2. DTC P1409: Measure Resistance Across EGRVR Solenoid -  Disconnect EGRVR solenoid 2-pin harness connector. Measure EGRVR solenoid resistance. If resistance reading is 26-40 ohms, value is within specification. Go to next step. If resistance reading is not 26-40 ohms, replace faulty EGRVR solenoid. After repair, go to step  8 .
  3. Check VPWR Circuit Voltage At EGRVR Solenoid -  With KOEO, measure voltage between EGRVR solenoid harness connector VPWR circuit (Light Blue/Orange wire) and chassis ground. See Fig 1 . Turn ignition off. If voltage reading is more than 10.5 volts, go to next step. If voltage reading is 10.5 volts or less, repair open in VPWR circuit. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. After repair, go to step  8 .
    Fig 1: Identifying EGRVR Solenoid Harness Connector
    G00155544Courtesy of MAZDA MOTORS CORP.
  4. Check EGRVR Circuit Resistance -  Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. See Figure . Measure resistance of EGRVR circuit (Brown/Pink wire) between breakout box terminal No. 47 and EGRVR solenoid harness connector. If resistance reading is less than 5 ohms, go to next step. If resistance reading is 5 ohms or more, repair open circuit in Brown/Pink wire between PCM 104-pin harness connector terminal No. 47 and EGRVR solenoid harness connector. After repair, go to step  8 .
  5. Check EGRVR Circuit For Short To Power In Harness -  With KOEO, measure voltage of EGRVR circuit between breakout box terminal No. 47 and negative battery terminal. If voltage reading is less than one volt, turn ignition off. Go to next step. If voltage reading is one volt or more, repair short circuit in Brown/Pink wire between PCM 104-pin harness connector terminal No. 47 and EGRVR solenoid harness connector. After repair, go to step  8 .
  6. Check EGRVR Circuit For Shorts To Ground -  Measure resistance between breakout box terminals No. 47 (EGRVR circuit) and 24 (PWR GND circuit), and 47 and 103 (PWR GND circuit). If resistance reading is more than 10,000 ohms, replace faulty PCM. After repair, go to step  8 . If resistance reading is 10,000 ohms or less, repair short to VPWR or PWR GND. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. After repair, go to step  8 .
  7. Wiggle EGRVR Solenoid While Monitoring VPWR -  Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. See Figure . With KOEO, measure voltage between breakout box terminals No. 47 (EGRVR circuit) and No. 24 (PWR GND circuit). Voltage reading must be more than 10.5 volts. To identify a fault, observe for voltage drop while lightly tapping on EGRVR solenoid, wiggling EGRVR solenoid connector, and wiggling EGRVR solenoid wires between solenoid and PCM. If a fault is indicated, isolate fault and repair as necessary. After repair, go to next step. If a fault is not indicated, unable to duplicate or identify a fault at this time. See INTERMITTENT  testing under SYSTEM TESTS.
  8. Verify Trouble Shooting Of DTCs Completed -  Reconnect all electrical connectors. Clear DTC from PCM memory. Perform QUICK TEST  under SELF-DIAGNOSTIC SYSTEM. If same DTC is present, replace faulty PCM. Repeat QUICK TEST  under SELF-DIAGNOSTIC SYSTEM. If any other DTC is present, go to applicable procedure for other DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS  . If no DTC is present, trouble shooting is complete.
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