Diagnostic Procedures
WARNING: This page is about a different car, the 2002 Mazda Tribute. However, it is still accessible from the selected car via links, so may be relevant.
- If QUICK TEST was not performed, go to QUICK TEST under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed, go to next step.
- DTCS P1132, P1152: Upstream HO2S(s) Not Switching
Check air intake system for leaks and damage. Verify integrity of PCV system. See POSITIVE CRANKCASE VENTILATION SYSTEM in SYSTEM TESTS . Check for vacuum leaks. If any concerns are present, repair as necessary. After repair, go to step 17. If concerns are not present, go to next step. - Perform KOER Self-Test
Disconnect fuel vapor hose from intake manifold and plug fitting at intake manifold. Start engine and run at 2000 RPM for 5 minutes and return to idle. Perform KOER self-test. If DTC P1132 and/or P1152 is present, go to next step. If DTC P1132 and/or P1152 are not present, perform EVAPORATIVE EMISSIONS SYSTEM LEAK TEST under SYSTEM TESTS (EVAPORATIVE EMISSION) in SYSTEM & COMPONENT TESTING - B2300, B3000, B4000 & TRIBUTE article. - HO2S Circuit Test (With Rich DTCs)
Turn ignition off. Disconnect suspect HO2S 4-pin harness connector related to DTC.- P1132 = HO2S11 (Front Bank 1)
- P1152 = HO2S21 (Front Bank 2)
Turn ignition on, engine off. Using scan tool, select DIAGNOSTIC DATA LINK. Select PCM. Select PIN/DATA MONITOR AND RECORD. Access O2S11 (Front Bank 1) or O2S21 (Front Bank 2) PID. Connect fused jumper wire between HO2S SIG (Red/Black wire) and HO2S VPWR (Light Blue/Orange wire) at HO2S 4-pin harness connector. See Figure. If voltage reading is 0.2 volt or less, go to step 6. If voltage reading is not as specified, go to next step.
- Check For Shorts To Voltage Source In Harness Circuit
Turn ignition off. Disconnect scan tool from DLC. Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. See Figure.- For DTC P1132, measure resistance between breakout box terminal No. 60 and terminals No. 71 (VPWR) and No. 93 (HTR11).
- For DTC 1152, measure resistance between breakout box terminal No. 87 and terminals No. 71 (VPWR) and No. 94 (HTR21).
If resistance reading is more than 10,000 ohms, replace PCM. After repair, go to step 17. If resistance reading is not as specified, replace HO2S. After repair, go to step 17.
- Check For HO2S Signal Shorted To HO2S Heater Circuit In Sensor
Reconnect suspect HO2S sensor 4-pin harness connector. Turn ignition on, engine off. Using scan tool, select DIAGNOSTIC DATA LINK. Select PCM. Select PID/DATA MONITOR AND RECORD. Access O2S11 (Front Bank 1) or O2S21 (Front Bank 2) PID. If HO2S voltage reading is more than 0.45 volt, replace HO2S. After repair, go to step 17. If voltage reading is not as specified, go to next step.WARNING: Fuel system is pressurized when engine is not running. To prevent injury or fire, use caution when working on fuel system.NOTE: During next step, fuel pump will only operate for approximately 8 seconds when Output Test Mode is selected and activated. - Check Fuel Pressure
Install fuel pressure gauge. Turn ignition on, engine off. Using scan tool, select DIAGNOSTIC DATA LINK. Select PCM. Select ACTIVE COMMAND MODES. Access OUTPUT TEST MODE and run fuel pump to obtain maximum fuel pressure. If fuel pressure is 55-70 psi, go to next step. If fuel pressure is not as specified, refer to FUEL DELIVERY SYSTEM testing under SYSTEM TESTS . - Check Injector Fault PIDs
Access INJ1F-INJ6F PIDs. If an injector(s) fault is present, go to next step. If an injector fault is not present, go to step 17.NOTE: Performing following procedure erases Continuous Memory DTCs.NOTE: Use injector fault PID to determine fuel injector circuit(s) requiring testing. - Check Fuel Injector(s) & Harness Resistance
Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. See Figure. Measure resistance of suspect fuel injector between suspect INJ circuit breakout box terminal and breakout box terminal No. 71 (VPWR). If resistance reading is 11-18 ohms, replace PCM. After repair, go to step 17. If resistance reading is not within specification, go to next step. - Check Fuel Injector Harness Resistance
Disconnect fuel injector harness connector at suspect fuel injector. Measure resistance of VPWR circuit (Red wire) between breakout box terminal No. 71 and fuel injector harness connector. Measure resistance of INJ circuit between appropriate breakout box terminal and fuel injector harness connector. See Figure. If each resistance reading is less than 5 ohms, go to next step. If each resistance reading is not as specified, repair open circuit. See WIRING DIAGRAMS article. After repair, go to step 17. - Check Fuel Injector Harness Circuit For Short To Power & Ground
Measure resistance between suspect INJ circuit breakout box terminal and breakout box terminal No. 71 (VPWR). Measure resistance between suspect INJ circuit breakout box terminal and breakout box terminal No. 103 (PWR GND). If each resistance reading is more than 10,000 ohms, go to next step. If each resistance reading is not as specified, replace fuel injector(s). After repair, go to step 17. - Flow Test Fuel Injector(s)
Use a fuel injector tester to flow test fuel injectors according to instructions for tester. Flow rate specification is 17 lb/hr. (7.8 kg/hr.) for 2.0L engines and 22 lb/hr. (10.1 kg/hr.) for 3.0L engines. If leakage and flow are within specification, go to next step. If leakage and flow are not within specification, replace fuel injector(s). After repair, go to step 17. - Attempt To Generate DTCS P1131 & P1151
Disconnect suspect HO2S 4-pin harness connector. Install fused jumper wire between negative battery post and HO2S 4-pin harness connector HO2S SIG terminal. Perform KOER self-test. If DTCs P1131 or P1151 are present, remove fused jumper wire and go to next step. If DTCs P1131 or P1132 are not present, remove fused jumper wire. Reconnect HO2S 4-pin harness connector. Disconnect PCM 104-pin harness connector. Inspect both ends for damaged or pushed out terminals, corrosion and loose wires. Repair as necessary. If connector, terminals and wiring are okay. Replace PCM. After repair, go to step 17. - HO2S Check
Connect DVOM to HO2S SIG and HO2S SIG RTN terminals at HO2S sensor 4-pin connector. See Figure. Disconnect any vacuum hose. Start engine and run at 2000 RPM. If voltage reading indicates less than 0.4 volt within 30 seconds, reconnect vacuum line and go to next step. If voltage reading is not as specified, replace HO2S. After repair, go to step 17. - Monitor HO2S (PID) For Proper Switching
Start engine. Warm up engine to operating temperature. Using scan, select DIAGNOSTIC DATA LINK. Select PCM. Select PID/DATA MONITOR AND RECORD. Access O2S11 (Front Bank 1) or O2S21 (Front Bank 2) PID and monitor while wiggling, bending and shaking small sections of engine harness from HO2S to PCM. Turn ignition off. If HO2S voltage reading did not stay high (more than 0.45 volt) or low (less than 0.45 volt), go to next step. If HO2S voltage reading stayed high or low, isolate cause for lack of switching and repair as necessary. After repair, go to step 21. - Test Drive While Monitoring HO2S PID For Proper Switching
Using scan tool, select DIAGNOSTIC DATA LINK. Select PCM. Select PID/DATA MONITOR AND RECORD. Access O2S11 (Front Bank 1) or O2S21 (Front Bank 2) PID. While observer views PID, test drive vehicle under different road conditions in an attempt to simulate original fault. If HO2S appears to switch properly, unable to duplicate problem. Go to next step. If HO2S does not appear to switch properly, replace 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 present, trouble shooting is complete.