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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 P1460: A/C Clutch Relay 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. NOTE: If vehicle is not equipped with A/C, the ACCR circuit is not used and DTC P1460 may be ignored.
  2. KOEO/KOER DTC P1460: Verify ACCS PID Is Off -  If Continuous Memory DTC P1460 is present, go to step  8 . For A/C always ON, see TEST NO. 4: A/C ALWAYS ON under TROUBLE SHOOTING in appropriate MANUAL A/C-HEATER SYSTEMS - B2300, B3000 & B4000 article in AIR-CONDITIONING & HEATING. Verify A/C and defrost were off during KOEO/KOER Self-Tests. Start engine. Ensure A/C and defroster are off. Using scan tool, select DIAGNOSTIC DATA LINK. Select PCM. Select PID/DATA MONITOR AND RECORD. Access and observe A/C Control Signal (ACCS) PID. If ACCS PID is off, turn ignition off. Go to next step. If ACCS PID is on, turn ignition off. Go to step  2 in DTC P1464: A/C CONTROL SIGNAL MALFUNCTION to check A/C circuits for short to power.
  3. Check For VPWR To A/C Clutch Relay -  Disconnect ACCR 5-pin harness connector. With KOEO, measure voltage of VPWR circuit between A/C clutch relay harness connector and chassis ground. See Fig 1 . 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. Reconnect ACCR. Start engine. Turn A/C on and wait 15 seconds. Turn A/C off. Turn off ignition. Go to step  10 .
    Fig 1: Identifying A/C Clutch Relay Circuits
    G00155555Courtesy of MAZDA MOTORS CORP.
  4. Check A/C Clutch Relay -  Turn ignition off. Reference pin numbers molded on ACCR. Measure resistance between ACCR terminals No. 1 and 2. Resistance reading should be 40-120 ohms. Check for continuity between ACCR terminals No. 3 and 4. Continuity should be present. Check for continuity between ACCR terminals No. 3 and 5. Continuity should not be present. If all measurements are okay, go to next step. If any measurement is not okay, replace faulty ACCR. Start engine. Turn A/C on and wait 15 seconds. Turn A/C off. Turn ignition off. Go to step  10 .
  5. Check A/C Clutch Circuit For Short To Power In Harness -  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 terminal No. 69 (ACCR circuit) and chassis ground. Turn ignition off. If voltage reading is less than one volt, go to next step. If voltage reading is one volt or more, repair short to power. Remove breakout box. Reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C off. Turn ignition off. Go to step  10 .
  6. Check ACCR Circuit For Short To Ground In Harness -  Disconnect scan tool from DLC. Measure resistance of ACCR circuit (Pink/Yellow wire) between A/C clutch relay 5-pin harness connector and ground. See Fig 1 . 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. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. Start engine. Turn A/C on and wait 15 seconds. Turn A/C off. Turn ignition off. Go to step  10 .
  7. Check ACCR Circuit Continuity -  Measure resistance of ACCR circuit (Pink/Yellow wire) between breakout box terminal No. 69 and ACCR 5-pin harness connector. See Fig 1 . If resistance reading is less than 5 ohms, replace faulty PCM. Reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C off. Turn ignition off. Go to step  10 . If resistance reading is 5 ohms or more, repair open circuit. Reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C off. Turn ignition off. Go to step  10 .
    8. NOTE: If vehicle is not equipped with A/C, ACCR circuit is not used and DTC P1460 may be ignored.
  8. Continuous Memory DTC P1460: Check ACCR Circuit For Intermittent Short To Ground -  With KOEO, check ACCR circuit for short to ground while shaking, wiggling and bending ACCR circuit between PCM and A/C clutch relay. Lightly tap on A/C clutch relay (to simulate road shock). A/C clutch will click on when a fault is indicated. If a fault is not indicated, go to next step. If a fault is indicated, repair wiring harness as necessary. Turn ignition off. Reconnect all components. Start engine. Turn A/C on and wait 15 seconds. Turn A/C off. Turn ignition off. Go to step  10 .
  9. Check ACCR Circuit For Intermittent Open Or Short To Power -  Using scan tool, select DIAGNOSTIC DATA LINK. Select PCM. Select ACTIVE COMMAND MODES. Access OUTPUT TEST MODE. Check ACCR circuit for open or short to power while shaking, wiggling and bending ACCR circuit between PCM and A/C clutch relay. Shake, wiggle and bend VPWR circuit (Pink/Yellow wire) to A/C clutch relay. See Fig 1 . Lightly tap on A/C clutch relay (to simulate road shock). A/C clutch will click off when a fault is indicated. If a fault is indicated, turn ignition off. Repair open or short circuit. See appropriate WIRING DIAGRAM under ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS. Start engine. Turn A/C on and wait 15 seconds. Turn A/C off. Turn ignition off. Go to next step. If a fault is not indicated, unable to duplicate or identify fault at this time. See INTERMITTENT  testing under SYSTEM TESTS.
  10. 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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