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Diagnostic Procedures

  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. NOTE: Verify A/C and defrost were off during Self-Test. If A/C or defrost were on, turn system off and rerun Self-Test.
  2. DTC P1464: Check ACCS PID -  Ensure A/C and defrost are turned off. With KOEO, using scan tool, select DIAGNOSTIC DATA LINK. Select PCM. Select PID/DATA MONITOR AND RECORD. Access and observe ACCS PID. If ACCS PID is on, go to next step. If ACCS PID is off, ACCS PID indicates ACCS input to PCM is low. Verify test results. With A/C and defrost off, rerun Self-Test where DTC P1464 was received. Go to step  7 .
  3. ACCS PID On: Disconnect A/C Cycling Switch & Check If ACCS PID Turns Off -  Turn ignition off. Disconnect A/C cycling switch 4-pin harness connector. With KOEO, using scan tool, select DIAGNOSTIC DATA LINK. Select PCM. Select PID/DATA MONITOR AND RECORD. Access and observe ACCS PID. If ACCS PID is on, go to next step. If ACCS PID is off, verify operation of A/C demand switch. If A/C demand switch is okay, repair short to power in A/C demand circuit to A/C cycling switch. See Fig 1 . See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. After repair, go to step  7 .
    Fig 1: Identifying A/C Circuits
    G00155556Courtesy of MAZDA MOTORS CORP.
  4. Check Power To A/C Clutch Circuit For Short To Power -  Turn ignition off. Disconnect A/C clutch relay. With KOEO, measure voltage between A/C clutch power circuit (Gray/White wire) in harness connector and chassis ground. See Fig 2 . Turn ignition off. If voltage reading was less than one volt, go to next step. If voltage reading was one volt or more, repair short circuit to power in Gray/White wire between A/C clutch relay 5-pin harness connector terminal No. 5 and ground terminal. After repair, go to step  7 .
    Fig 2: Identifying A/C Clutch Relay Circuits
    G00155555Courtesy of MAZDA MOTORS CORP.
  5. Check ACCS Circuit For Short To Power -  Turn ignition off. 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. 41 (ACCS circuit) and 103 (PWR GND circuit). Turn ignition off. If voltage reading was less than one volt, go to next step. If voltage reading was one volt or more, repair ACCS short circuit to power. After repair, go to step  7 .
  6. Check ACCS Circuit Voltage To PCM With A/C Clutch Relay Connected -  Reconnect A/C clutch relay 5-pin harness connector. With KOEO, measure voltage between breakout box terminals No. 41 (ACCS circuit) and 103 (PWR GND circuit). Turn ignition off. If voltage reading was less than one volt, replace faulty PCM. After repair, go to next step. If voltage reading was one volt or more, replace faulty A/C clutch relay. After repair, go to next step.
  7. Verify Trouble Shooting Of DTCs Completed -  Reconnect all electrical connectors. Using scan tool, clear DTC from PCM memory. Perform QUICK TEST  under SELF-DIAGNOSTIC SYSTEM. If same DTC is present, replace faulty PCM and 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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