Mazda CX-7 2007 Workshop Manual page 123

DTC P0133[L3 WITH TC]
DTC P0133 Front HO2S circuit slow response
• An oxygen sensor malfunction can be detected by measuring the average frequency of the oxygen sensor
signal, time required to pass from rich to lean, and the time required to pass from lean to rich.
• The average frequency of the oxygen sensor signal is more than the threshold value.
MONITORING CONDITIONS
— HO2S heater, HO2S, and TWC Repair Verification Drive Mode
— The following conditions are met:
• Front HO2S heater monitor is completed.
• ECT sensor and front HO2S heater are normal
• Engine speed: 1,750— 3,500 rpm.
• Charging efficiency: 35— 63% (at engine speed of 2,500 rpm)
DETECTION
• Fuel system loop status is closed loop fuel control.
CONDITION
• Engine coolant temperature above 70 °C {158 °F}
Diagnostic support note
• This is an intermittent monitor (HO2S).
• The MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or
in one drive cycle while the DTC for the same malfunction has been stored in the PCM.
• DIAGNOSTIC MONITORING TEST RESULTS is available.
• PENDING CODE is available if the PCM detects the above malfunction condition during first drive cycle.
• FREEZE FRAME DATA is available.
• DTCs are stored in the PCM memory.
• Front HO2S deterioration
• Front HO2S malfunction
• Front HO2S looseness
• Fuel pressure sensor malfunction
• Clogged or restricted fuel line
POSSIBLE
• Fuel leakage in the fuel line between the fuel delivery pipe and the fuel pump
CAUSE
• Exhaust system leakage
• Purge solenoid valve malfunction
• Improper connection purge solenoid hose
• Insufficient compression
• Engine malfunction (Engine coolant leakage)
Diagnostic procedure
STEP
1 VERIFY FREEZE FRAME DATA AND
DIAGNOSTIC MONITORING TEST RESULTS
HAVE BEEN RECORDED
• Have the FREEZE FRAME DATA and
DIAGNOSTIC MONITORING TEST RESULTS
(HO2S related) been recorded?
2 VERIFY RELATED REPAIR INFORMATION
AVAILABILITY
• Verify related Service Bulletins and/or on-line
repair information availability.
• Is any related repair information available?
3 VERIFY RELATED PENDING AND STORED
DTC
• Turn the ignition switch off, then to the ON
position (Engine off).
• Verify the pending or stored DTCs using the M-
MDS.
• Is DTC P0443 also present?
4 IDENTIFY TRIGGER DTC FOR FREEZE FRAME
DATA
• Is DTC P0133 on FREEZE FRAME DATA?
ON-BOARD DIAGNOSTIC [L3 WITH TC]
INSPECTION
Yes Go to the next step.
No Record the FREEZE FRAME DATA and DIAGNOSTIC
MONITORING TEST RESULTS on the repair order, then
go to the next step.
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 Go to DTC P0443 troubleshooting procedures, then go to
Step 14.
No Go to the next step.
Yes Go to the next step.
No Go to troubleshooting procedures for DTC on FREEZE
FRAME DATA.
(See01-02-13 DTC TABLE[L3 WITH TC].)
id010239804800
ACTION
01-02–81
01-02