Leak Detection Pump

Disconnect negative battery cable. Remove EVAP system leak detection pump.

1. Air Flow Inspection
   
   Blow air into port "A" (charcoal canister side). Air should flow from port "B". See Fig 1 . If air does not flow from port "B" (air filter side), replace EVAP system leak detection pump. Blow air into port "B". Air should flow from port "A". If air does not flow from port "A", replace EVAP system leak detection pump. If EVAP system leak detection pump is as specified, go to next step.
   Fig 1: Identifying EVAP System Leak Detection Pump Ports (MPV)

   Courtesy of MAZDA MOTORS CORP.
2. Resistance Inspection
   
   Disconnect negative battery cable. Disconnect EVAP system leak detection pump connector. Using DVOM, check resistance between appropriate terminals on EVAP system leak detection pump. See Fig 2 . See EVAP SYSTEM LEAK DETECTION PUMP RESISTANCE SPECIFICATION  table. If resistance readings are not as specified, replace EVAP system leak detection pump. If resistance readings are within specification, check for open or short circuit in wiring harness. Disconnect PCM and install 104-Pin Breakout Box (49-UN01-130) between PCM and PCM harness connector. See Figure . Go to next step.
   Fig 2: Identifying EVAP System Leak Detection Pump Connector Terminals (MPV)

   Courtesy of MAZDA MOTORS CORP.
   EVAP SYSTEM LEAK DETECTION PUMP RESISTANCE SPECIFICATION
   
   

   Terminals	Resistance (ohms)
   A-B	20-25
   A-C	26.6-32.4
   A-D	About 118

3. Open Circuit Inspection
   
   Check continuity between following terminals.
   • EVAP system leak detection pump terminal "A" (White/Red wire) and main relay terminal "D" (Yellow wire).
   • EVAP system leak detection pump terminal "B" (Black wire) and ground.
   • EVAP system leak detection pump terminal "C" (Red/Blue wire) and breakout box terminal No. 67.
   • EVAP system leak detection pump terminal "D" (Pink/Blue wire) and breakout box terminal No. 43.

   See Fig 3 . See WIRING DIAGRAMS article. If continuity is not present, repair or replace open wiring harness.

   Fig 3: Identifying EVAP System Leak Detection Pump Harness Connector Terminals - MPV (Terminal View)

   Courtesy of MAZDA MOTORS CORP.
4. Short Circuit Inspection
   
   Check for continuity between following:
   • EVAP system leak detection pump terminals "B" (Black wire), "C" (Red/Blue wire) and "D" (Pink/Blue wire) and power.
   • EVAP system leak detection pump terminal "A" (White/Red wire) and ground.

   If continuity is present, repair or replace shorted wiring harness.