Mazda CX-7 2007 Workshop Manual page 71

STEP
2 VERIFY RELATED REPAIR INFORMATION
AVAILABILITY
• Verify related Service Bulletins and/or on-line
repair information availability.
• Is any related repair information available?
3 INSPECT FRONT HO2S CONNECTOR FOR
POOR CONNECTION
• Turn the ignition switch off.
• Disconnect the front HO2S connector.
• Inspect for poor connection (such as damaged/
pulled-out pins, and corrosion).
• Is there any malfunction?
4 INSPECT FRONT HO2S HEATER POWER
CIRCUIT FOR OPEN CIRCUIT OR SHORT TO
GROUND
• Turn the ignition switch to the ON position
(Engine off).
• Measure the voltage between front HO2S
terminal 2B (wiring harness-side) and body
ground.
• Is the voltage B+?
5 INSPECT FRONT HO2S HEATER CONTROL
CIRCUIT FOR SHORT TO GROUND
• Turn the ignition switch off.
• Inspect for continuity between front HO2S
terminal 2D (wiring harness-side) and body
ground.
• Is there continuity?
6 INSPECT FRONT HO2S HEATER
• Inspect the front HO2S heater.
(See01-40-37 HEATED OXYGEN SENSOR
(HO2S) INSPECTION[L3 WITH TC].)
• Is there any malfunction?
7 INSPECT PCM CONNECTOR FOR POOR
CONNECTION
• Turn the ignition switch off.
• Disconnect the PCM connector.
• Inspect for poor connection (such as damaged/
pulled-out pins, and corrosion).
• Is there any malfunction?
8 INSPECT FRONT HO2S HEATER CONTROL
CIRCUIT FOR OPEN CIRCUIT
• Turn the ignition switch off.
• Inspect for continuity between front HO2S
terminal 2D (wiring harness-side) and PCM
terminal 2C (wiring harness-side).
• Is there continuity?
9 VERIFY TROUBLESHOOTING OF DTC P0031
COMPLETED
• Make sure to reconnect all disconnected
connectors.
• Clear the DTC from the PCM memory using
the M-MDS.
• Perform the HO2S heater, HO2S, and TWC
Repair Verification Drive Mode.
(See01-02-10 OBD-II DRIVE MODE[L3 WITH
TC].)
• Is the PENDING CODE for this DTC present?
10 VERIFY AFTER REPAIR PROCEDURE
• Perform the "AFTER REPAIR PROCEDURE".
(See01-02-10 AFTER REPAIR
PROCEDURE[L3 WITH TC].)
• Are any DTCs present?
End Of Sie
ON-BOARD DIAGNOSTIC [L3 WITH TC]
INSPECTION
Yes Perform the repair or diagnosis according to the available
repair information.
• If the vehicle is not repaired, go to the next step.
No Go to the next step.
Yes Repair or replace the terminal, then go to Step 9.
No Go to the next step.
Yes Go to the next step.
No Repair or replace the wiring harness for a possible open
circuit or short to ground, then go to Step 9.
Yes Repair or replace the wiring harness for a possible short to
ground, then go to Step 9.
No Go to the next step.
Yes Replace the front HO2S, then go to Step 9.
(See01-15-2 EXHAUST SYSTEM REMOVAL/
INSTALLATION[L3 WITH TC].)
No Go to the next step.
Yes Repair or replace the terminal, then go to Step 9.
No Go to the next step.
Yes Go to the next step.
No Repair or replace the wiring harness for a possible open
circuit, then go to the next step.
Yes Replace the PCM, then go to the next step.
(See01-40-6 PCM REMOVAL/INSTALLATION[L3 WITH
TC].)
No Go to the next step.
Yes Go to the applicable DTC inspection.
(See01-02-13 DTC TABLE[L3 WITH TC].)
No DTC troubleshooting completed.
ACTION
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01-02