Maintenance Manual for J2 Sedan
Electronic Control System
of Engine
213
Fault code: P0134 “the upstream oxygen sensor signal is in trouble”
S/N
Step
Check result
Subsequent step
1
Connect the diagnosis device and adapter, and turn the ignition switch
to ON position.
Next step
Yes
Diagnosis help
2
Start the engine and run the engine idly till the coolant temperature
reaches to the normal value. Observe the change of the value of
“Oxygen sensor voltage” on the diagnosis meter, and at this moment,
the displayed value shall change fast between 100mV and 900mV.
No
Next step
Yes
Repair or replace
the harness
3
Check if the circuits connecting Pins 39# and 45# of ECU
respectively to Pin 3# (relative to gray connecting wire of oxygen
sensor) and Pin 4# (relative to black connecting wire of oxygen
sensor) of sensor connector are open.
No
Diagnosis help
Fault code: P0171 “the closed loop control self leaning of off-line air/fuel ratio test is too infrequent”
(Note: the following diagnosis procedures are applicable to the case that the fault codes of intake
pressure sensor, canister control valve, oxygen sensor and so on do not occur together; if the relevant
fault codes exist at the same moment, please firstly solve other faults and then make check and repair
according to the following procedure.)
S/N
Step
Check result
Subsequent step
1
Connect the diagnosis device and adapter, and turn the ignition switch
to ON position.
Next step
Yes
Next step
2
Start the engine and run the engine idly till the coolant temperature
reaches to the normal value.
Under all the work conditions, observe the change of the value of
“Oxygen sensor voltage” on the diagnosis meter, and at this moment,
check if the displayed value remains at 100mV or so for a long time
under a certain condition.
No
Diagnosis help
Yes
Next step
3
Connect the fuel pressure meter to the fuel system inlet pipe, and
observe if the fuel pressure remains at 350kPa or so under all the
work conditions.
No
Check and repair
the fuel system
Yes
Repair or replace
the harness
4
Check if the circuits connecting Pins 39# and 45# of ECU
respectively to Pin 3# (relative to gray connecting wire of oxygen
sensor) and Pin 4# (relative to black connecting wire of oxygen
sensor) of sensor connector are short to ground.
No
Next step
Yes
Make check and
repair according
to diagnosis
results.
5
A. Check if the intake system has serious leakage;
B. Check if the fuel injector is blocked.
C. Check if the spark plug clearance is too big.
D. Check if the resistance of live wire branch is too high.
E. Check if the intake valve guide is worn.
Etc.
No
Diagnosis help
Fault code: P0172 “the closed loop control self leaning of off-line air/fuel ratio test is too frequent”
(Note: the following diagnosis procedures are applicable to the case that the fault codes of intake
pressure sensor, canister control valve, oxygen sensor and so on do not occur together; if the relevant
fault codes exist at the same moment, please firstly solve other faults and then make check and repair
according to the following procedure.)
