Diagnostic Procedures
- If QUICK TEST was not performed, go to QUICK TEST under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed, go to next step.
- DTCs P0131 & P0151: Contaminated HO2S/Voltage Shift
DTC P0131 (right front HO2S-11) and DTC P0151 (left front HO2S-21). For HO2S locations, see Fig 1. Check for water in HO2S 4-pin harness connectors. If water is not present in connector, go to next step. If water is present in HO2S connector, dry out connector and repair source of water leak. If problem cannot be repaired, replace HO2S. After repair, go to step 4.
- Verify Wiring Is In Proper Pin Location
Disconnect 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. See Figure. Measure resistance of HO2S SIG circuit between breakout box terminal No. 60 (DTC P0131) or No. 87 (DTC P0151) and HO2S 4-pin harness connector. See Fig 2. Record measurement. Measure resistance of SIG RTN circuit (Orange wire) between breakout box terminal No. 91 and HO2S 4-pin harness connector. Record measurement. If resistance reading is 5 ohms or more, repair open circuit. See WIRING DIAGRAMS
article. After repair, go to next step. If resistance reading is less than 5 ohms, replace suspect HO2S. After repair, go to next step.
- 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 set, procedure is complete.
Courtesy of MAZDA MOTORS CORP.
Courtesy of MAZDA MOTORS CORP.