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Home >> Mazda >> 2007 >> B4000 SE, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 70 (Engine Controls - Self-Diagnostics) >> Diagnostic Tests >> DTC P1451: Canister Vent Solenoid Malfunction >> Diagnostic Procedures

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, go to next step.
  2. DTC P1451: Check VPWR Voltage To Canister Vent Solenoid -  Turn ignition off. Disconnect EVAP CV solenoid 2-pin harness connector. Connect a non-powered test light between CV circuit (Violet/White wire) and VPWR circuit (Light Blue/Orange wire) at EVAP CV solenoid harness connector. See Fig 1 . With KOEO, using scan tool, select DIAGNOSTIC DATA LINK. Select PCM. Select PID/DATA MONITOR AND RECORD. Attempt to close and open EVAP CV solenoid driver in PCM by accessing OUTPUT TEST MODE. Select ALL OFF mode. Cycle START button on and off, and observe test light. If test light cycles on and off, turn ignition off. Go to next step. If test light does not cycle on and off:
    • For test light always off, go to step  4 .
    • For test light always on, turn ignition off. Go to step  8 .
  3. Check CV Solenoid Resistance -  Measure EVAP CV solenoid resistance. If resistance reading is 45-65 ohms, unable to identify fault at this time. See INTERMITTENT  testing under SYSTEM TESTS. If resistance reading is not 45-65 ohms, replace faulty EVAP CV solenoid. After repair, go to step  10 .
    4. NOTE: Wire color changes from Red to Light Blue/Orange at splice in wire harness after under hood battery junction box. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS.
    Fig 1: Identifying EVAP CV Solenoid Harness Connector & Circuits
    G00155554Courtesy of MAZDA MOTORS CORP.
  4. Check For Open VPWR Circuit Between EVAP CV Solenoid & Power Relay -  Measure voltage of VPWR circuit between EVAP CV solenoid harness connector (Light Blue/Orange wire) and negative battery terminal. See Fig 1 . If voltage reading is more than 10.5 volts, turn ignition off. Go to next step. If voltage reading is 10.5 volts or less, turn ignition off. Repair open circuit between PCM 104-pin harness connector terminal No. 71 (Red wire) and EVAP CV solenoid harness connector (Light Blue/Orange wire). See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. After repair, go to step  10 .
  5. Check VPWR Circuit For Opening In Harness -  Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. See Figure . Measure resistance of VPWR circuit between breakout box terminal No. 71 and EVAP CV solenoid harness connector (Light Blue/Orange wire). See Fig 1 . If resistance reading is less than 5 ohms, go to next step. If resistance reading is 5 ohms or more, repair open circuit between PCM 104-pin harness connector terminal No. 71 (Red wire) and EVAP CV solenoid harness connector (Light Blue wire). After repair, go to step  10 .
  6. Check EVAP CV Circuit For Open In Harness -  Measure resistance of EVAP CV circuit between breakout box terminal No. 67 and EVAP CV solenoid harness connector (Violet/White wire). If resistance reading is less than 5 ohms, replace faulty PCM. After repair, go to next step. If resistance reading is 5 ohms or more, repair open circuit in Violet/White wire between PCM 104-pin harness connector terminal No. 67 and EVAP CV solenoid harness connector. After repair, go to step  10 .
  7. Check EVAP CV Circuit For Short To VPWR -  With KOEO, measure voltage of EVAP CV circuit (Violet/White wire) between EVAP CV solenoid harness connector and chassis ground. If voltage reading is less than one volt, replace faulty PCM. After repair, go to step  10 . If voltage reading is one volt or more, repair short to VPWR in Violet/White wire between PCM 104-pin harness connector terminal No. 67 and EVAP CV solenoid harness connector. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. After repair, go to step  10 .
  8. Check Circuit For Short To PWR GND In Harness -  Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. See Figure . Measure resistance of EVAP CV circuit between EVAP CV solenoid harness connector and battery negative terminal. If resistance reading is more than 10,000 ohms, go to next step. If resistance reading is 10,000 ohms or less, repair short circuit in Violet/White wire between PCM 104-pin harness connector terminal No. 67 and EVAP CV solenoid harness connector. After repair, go to step  10 .
  9. Check Circuit For Short To Power -  Reconnect scan tool. With KOEO, measure voltage of EVAP CV circuit (Violet/White wire) between EVAP CV solenoid harness connector and battery ground. Turn ignition off. If voltage reading is less than one volt, replace faulty PCM. After repair, go to next step. If voltage reading is one volt or more, repair short circuit to VPWR, VREF or chassis ground in Violet/White wire between PCM 104-pin harness connector terminal No. 67 and EVAP CV solenoid harness connector. After repair, go to next step.
  10. 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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