LEMON Manuals: Even more car manuals for everyone
Home >> Mazda >> 2004 >> RX-8 1.3 3 >> Repair and Diagnosis >> External Pages >> Different car >> Section 66 (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 Tribute. 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 CV solenoid. Connect a non-powered test lamp between CV and VPWR circuits at CV solenoid 2-pin harness connector. Connect scan tool to DLC. Turn ignition on, engine off. Select DIAGNOSTIC DATA LINK. Select PCM. Select PID/DATA MONITOR AND RECORD. Attempt to close and open CV solenoid driver in PCM by accessing OUTPUT TEST MODE. Select ALL OFF mode. Cycle START button ON and OFF, and observe test lamp. If test lamp cycles on and off (light up and turn off), turn ignition off and go to next step. If test lamp is always off, go to step  4. If test lamp is always on, turn ignition off and go to step  8.
  3. Check CV Solenoid Resistance -  Measure CV solenoid resistance. If resistance reading is 45-65 ohms, problem is intermittent. Refer to INTERMITTENT  testing under SYSTEM TESTS. If resistance reading is not as specified, replace damaged CV solenoid.
  4. Check For Open VPWR Circuit Between CV Solenoid & Power Relay -  Measure voltage of VPWR circuit (Light Blue/Orange wire) between CV solenoid harness connector and negative battery terminal. See Fig 1. If voltage reading is more than 10.5 volts, turn ignition off and go to next step. If voltage reading is not as specified, repair open circuit in Light Blue/Orange wire between PCM power relay and CV solenoid harness connector. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. After repair, go to step  10.
    Fig 1: Identifying CV Solenoid Circuits & Harness Connector Terminals
    G00035605Courtesy of FORD MOTOR CO.
  5. Check VPWR Circuit For Open 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 CV solenoid harness connector (Light Blue/Orange wire). If resistance reading is less than 5 ohms, go to next step. If resistance reading is not as specified, repair open circuit between PCM 104-pin harness connector terminal No. 71 (White/Red wire) and CV solenoid harness connector (Light Blue/Orange wire). After repair, go to step  10.
  6. Check CV Circuit For Open In Harness -  Measure resistance of CV circuit between breakout box terminal No. 67 and CV solenoid harness connector (Purple/White wire). See Fig 1. If resistance reading is less than 5 ohms, replace PCM. After repair, go to next step. If resistance reading is not as specified, repair open circuit in Purple/White wire between PCM 104-pin harness connector terminal No. 67 and CV solenoid harness connector. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. After repair, go to step  10.
  7. Check CV Circuit For Short To VPWR -  Turn ignition on, engine off. Measure voltage of CV circuit between ground and CV solenoid harness connector. If voltage reading is less than one volt, replace PCM. After repair, go to step  10. If voltage reading is one volt or more, repair short circuit to VPWR in Violet/White wire between PCM 104-pin harness connector terminal No. 67 and CV solenoid harness connector. After repair, go to step  10.
  8. Check CV Circuit For Short To PWR GND In Harness -  Disconnect PCM 104-pin harness connector. Disconnect scan tool from DLC. Measure resistance of CV circuit (Purple/White wire) between CV solenoid harness connector and negative battery terminal. See Fig 1. If resistance reading is more than 10,000 ohms, go to next step. If resistance reading is not as specified, repair short circuit in Purple/White wire between PCM 104-pin harness connector terminal No. 67 and CV solenoid harness connector. After repair, go to step  10.
  9. Check Circuit For Short To Power -  Reconnect scan tool. Turn ignition on, engine off. Measure voltage of CV circuit (Purple/White wire) between CV solenoid harness connector and ground. Turn ignition off. If voltage reading was less than one volt, replace PCM. After repair, go to next step. If voltage reading was not as specified, repair short circuit to VPWR, VREF or ground in Purple/White wire between PCM 104-pin harness connector terminal No. 67 and CV solenoid harness connector. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. After repair, go to next step.
  10. Verify Trouble Shooting Of DTCs Completed -  Reconnect all disconnected connectors. Clear DTCs from PCM memory using scan tool. Perform QUICK TEST  under SELF-DIAGNOSTIC SYSTEM. If same DTC is present, replace faulty PCM. Repeat QUICK TEST  under SELF-DIAGNOSTIC SYSTEM. If same DTC is not present, go to applicable procedure for other DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no DTCs are present, trouble shooting is complete.
scientia non olet · About LEMON Manuals