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Home >> Mazda >> 2002 >> Tribute LX, 4WD >> Repair and Diagnosis >> External Pages >> Different car >> Section 60 (Engine Controls [Self-Diagnostics 2.3L]) >> Diagnostic Tests >> DTC P0481: Fan Relay No. 2 & No. 3 Control Circuit - Malfunction >> Diagnostic Procedure

Diagnostic Procedure

WARNING: This page is about a different car, the 2003 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.
  1. If FREEZE FRAME DATA has been recorded, go to next step. If FREEZE FRAME DATA has not been recorded, record FREEZE FRAME DATA. Go to next step.
  2. Verify Related Repair Information Availability -  Check for related Service Bulletins and/or on-line repair information availability. If any related repair information is available, perform repair or diagnosis according to available repair information. If vehicle is not repaired, go to next step. If related repair information is not available, go to next step.
  3. Inspect Cooling Fan Relay No. 2 & No. 3 Connector For Poor Connection -  Turn ignition off. Disconnect cooling fan relays No. 2 and 3 harness connectors. Check for poor connection (such as damaged, pulled-out pins, corrosion). If terminals are okay, go to next step. If malfunction is present, repair or replace suspected terminal. After repair, go to step  10.
  4. Inspect Cooling Fan Relay No. 2 & No. 3 Power Circuit For Open -  Turn ignition on, engine off. Measure voltage in Green/Black wire between following terminals and body ground. See Fig 1.
    • Cooling fan relay No. 2 harness connector terminal "A"
    • Cooling fan relay No. 3 harness connector terminal "E"
    If battery voltage is present at both cooling fan relay terminals, go to next step. If battery voltage is not present at both terminals, repair open circuit in Green/Black wire between ignition switch and suspected cooling fan relay terminal or replace wire harness. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. After repair, go to step  10.
    Fig 1: Identifying Cooling Fan Relays No. 2 & No. 3 Circuits & Harness Connector Terminals
    G00221510Courtesy of MAZDA MOTORS CORP.
  5. Inspect Cooling Fan Relays No. 2 & No. 3 -  Inspect cooling fan relays No. 2 and No. 3. Refer to COOLING FAN under MISCELLANEOUS CONTROLS in SYSTEM & COMPONENT TESTING - MAZDA6, MIATA, MPV, PROTEGE & PROTEGE5 article. If cooling fan relays No. 2 and No. 3 are okay, go to next step. If cooling fan relay No. 2 or No. 3 is faulty, replace faulty cooling fan relay. After repair, go to step  10.
  6. Inspect Cooling Fan Relay No. 2 & No. 3 Control Circuit For Short To Power -  Measure voltage in Gray/Blue wire between following terminals and body ground.
    • Cooling fan relay No. 2 harness connector terminal "E"
    • Cooling fan relay No. 3 harness connector terminal "A"
    If battery voltage is not present, go to next step. If battery voltage is present, repair short circuit to power in Gray/Blue wire between cooling fan relays No. 2 or No. 3 and PCM 30-pin harness connector terminal "4F" or replace wire harness. After repair, go to step  10.
  7. Inspect Cooling Fan Relay No. 2 & No. 3 Control Circuit For Short To Ground -  Inspect continuity between following terminals and body ground. See Fig 1.
    • Cooling fan relay No. 2 harness connector terminal "E"
    • Cooling fan relay No. 3 harness connector terminal "A"
    If continuity is present, repair short circuit to ground in Gray/Blue wire between suspected cooling fan relay No. 2 or No. 3 harness connector terminal and PCM 30-pin harness connector terminal "4F" or replace wire harness. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. After repair, go to step  10.
  8. Inspect PCM Connectors For Poor Connection -  Turn ignition off. Disconnect PCM harness connectors. Check for poor connection (such as damaged, pulled-out pins, corrosion). If terminals are okay, go to next step. If malfunction is present, repair or replace terminal/connector. After repair, go to step  10.
  9. Inspect Cooling Fan Relay No. 2 And No. 3 Control Circuit For Open Circuit -  Check for continuity in Gray/Blue wire between following terminals and PCM 30-pin harness connector terminal "4F".
    • Cooling fan relay No. 2 harness connector terminal "E"
    • Cooling fan relay No. 3 harness connector terminal "A"
    If continuity is present, go to next step. If continuity is not present, repair open circuit in Gray/Blue wire between suspected cooling fan relay harness connector terminal and PCM 30-pin harness connector terminal "4F". After repair, go to step  10.
  10. Verify Trouble Shooting Of DTC P0481 Is Completed -  Make sure to reconnect all disconnected connectors. Clear DTC from PCM memory using WDS or equivalent. Turn ignition off. Start engine and turn on A/C switch and fan switch. If PENDING CODE of same DTC is not present, go to next step. If PENDING CODE of same DTC is present, replace PCM. For PCM removal and installation, see POWERTRAIN CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS in REMOVAL & INSTALLATION article. After repair, go to next step.
  11. Verify After Repair Procedure -  Using scan tool, perform After Repair Procedure. See AFTER REPAIR PROCEDURE . If any DTCs are present, go to appropriate DTC inspection. Refer to DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no DTCs are present, trouble shooting is complete.
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