Page 757 of 1903
Downloaded from www.Manualslib.com manuals search engine 4.CHECK THE O2SENSOR GROUND CIRCUIT FOR AN OPEN OR SHORT
• Disconnect ECM harness connector.
• Check harness continuity between upstream O
2sensor terminal 1 in connector E-074 and ECM terminal 76 in
connector E-054.
• Check harness continuity between downstream O
2sensor terminal 1 in connector B-011 and ground.
• Continuity should exist.
• Check harness for a short to power and short to ground.
Is the check result normal?
Ye s>>Go to the next step.
No
>>Repair the circuits for an open or short to power or short to ground in harness or connectors.
5.CHECK THE O2SENSOR INPUT SIGNAL CIRCUIT FOR AN OPEN OR SHORT
• Check harness continuity between ECM terminal and O
2sensor terminal as follows.
• Continuity should exist.
• Check harness continuity between following terminals and ground.
• Continuity should not exist.
COMPONENT ECM TERMINALO2SENSOR TERMINAL
Upstream O
2sensor 60 4
Downstream O
2sensor 59 4
• Also Check harness short to power supply circuit.
Is the check result normal?
Ye s>>Go to the next step.
No
>>Repair circuit for an open or short to power or short to ground in harness or connectors.
6.CHECK O2SENSOR POWER SUPPLY
• Turn ignition switch on.
• Check power supply between O
2sensor E-074, ter-
minal 2 and ground.
• Battery voltage should exist.
Is the check result normal?
Ye s>>Go to step 8.
No
>>Go to the next step.
DIAGNOSIS & TESTING
LTSMD030002
03
03–473Chery Automobile Co., Ltd.
Page 758 of 1903
Downloaded from www.Manualslib.com manuals search engine 7.DETECT MALFUNCTIONING PART
• Check the following:
Fuse 25, Fuse 12, Fuse 24
Front fuse and relay box H5
Harness connectors A-102, E-105
Harness open or short between O
2sensor and fuse
Is the check result normal?
Ye s>>Go to the next step.
No
>>Repair or replace malfunctioning parts.
8.CHECK O2SENSOR HEATER CONTROL CIRCUIT FOR AN OPEN AND SHORT
• Turn ignition switch off.
• Check harness continuity between ECM terminal and O
2sensor terminal.
COMPONENTS ECMO2SENSOR
TERMINAL 523
• Continuity should exist.
• Check harness short to power supply circuit and ground.
Is the check result normal?
Ye s>>Go to the next step.
No
>>Repair the circuit for an open or short to power supply circuit or ground in harness or connectors.
9.CHECK O2SENSOR HEATER
• Check resistance between O
2sensor terminals.
TERMINAL NO. RESISTANCE
2 & 3 (including cable and
connector) Approximately 9
1&2and1&3 (Continuity should notexist)
4&2and4&3
Is the check result normal?
Ye s>>Go to the next step.
No
>>Replace O2sensor.
DIAGNOSIS & TESTING
03–474Chery Automobile Co., Ltd.
Page 759 of 1903
Downloaded from www.Manualslib.com manuals search engine 10. CHECK O2SENSOR
• Connect O
2sensor connector.
• Connect ECM connector.
• If with the X-431, reference data stream value.
• If without the X-431, as following.
Start engine and warm it up to normal operating temperature.
Turn ignition switch off.
Start engine and keep the engine speed between 3.500 and 4,000 RPM for at least 1 minute.
Let engine idle for 1 minute.
Set digital multimeter probes between ECM terminal 60 and ground.
CHECK ITEM CHECK CONTENT NORMAL VALUE
Oxygen sensor •
Warm-up condition
• Become lean while
decelerate Decelerate from 4,000
RPM suddenly below 200 mV
• Warm-up condition
• Become rich while
accelerate Accelerate suddenly
600 - 1,000 mV
• Warm-up condition
• Check with O
2sensor
signal Idle
100 - 900 mV
2500 RPM 600 - 1,000 mV
Is the check result normal?
Ye s>>Go to the next step.
No
>>Replace O2sensor.
11 . CHECK DTC
• With the X-431 scan tool, read ECM DTCs.
• Refer to DTC Confirmation Procedure.
Is DTC 11 still present?
Ye s>>Replace the ECM.
No
>>The system is now operating properly.
Reassemble the vehicle and road test to verify the customers complaint is repaired.
DIAGNOSIS & TESTING
03
03–475Chery Automobile Co., Ltd.
Page 761 of 1903
Downloaded from www.Manualslib.com manuals search engine Check reference values between ECM terminals and ground under the following conditions:
ECM TERMINAL NO.ITEMCONDITIONDATA (DC VOLTAGE)
19 Air flow sensor •
Engine is running
• Warm-up condition
• Idle 0-1V
• Engine is running: 3,000
RPM 6-9V
74 Air flow sensor •
Engine is running
• Warm-up condition
• Idle
2.2 - 3.2 V
• Engine is running: 2,500
RPM
On Board Diagnostic Logic
• Self-diagnosis detection logic.
DTC NO. DTC DEFINITION DTC DETECTION
CONDITION DTC SET
CONDITION POSSIBLE CAUSE
12 Air flow sensor Engine speed is
above 500 RPM Sensor output
frequency is below 3 HZ for 4 seconds. •
Air flow sensor
• Harness or
connectors
• ECM
DTC Confirmation Procedure:
Before performing the following procedure, confirm that battery voltage is more than 12 V.
• Turn ignition switch off.
• Connect the X-431 scan tool to the Data Link Connector (DLC) - use the most current software available.
• Turn ignition switch on and record and erase DTC.
• Start engine and keep the engine speed above 500 RPM and select view DTC and data stream.
• If the DTC is detected, the DTC condition is current. Go to Diagnostic Procedure - Step 1.
• If the DTC is not detected, the DTC condition is intermittent (See Diagnostic Help and Intermittent DTC Trou-
bleshooting in Section 03 Electronic Engine Controls for more information.
NOTE :
Before performing the following procedure, make sure that the ECM connection is in good condition.
NOTE :
While performing electrical diagnosis & testing, always refer to the electrical schematics for specific circuit
and component information.
Diagnostic Procedure
1.CHECK GROUND CONNECTION
• Turn ignition switch off.
• Loosen and retighten ground screws on the body (See Ground Inspection in Section 03 Electronic Engine Con-
trols).
• Inspect the ground connection E-208 (See Vehicle Wiring Harness Layout - Engine Room Harness (With Mit-
subishi 2.4L Engine) in Section 16 Wiring).
Is the ground connections OK?
Ye s>>Go to the next step.
No
>>Repair or replace ground connection.
DIAGNOSIS & TESTING
03
03–477Chery Automobile Co., Ltd.
Page 762 of 1903
Downloaded from www.Manualslib.com manuals search engine 2.CHECK AIR FLOW SENSOR ELECTRICAL CONNECTOR
• Turn ignition switch off.
• Disconnect the air flow sensor electrical connector.
• Inspect the electrical connector for damage.
Is the electrical connector OK?
Ye s>>Go to the next step.
No
>>Repair or replace the electrical connector as necessary.
3.CHECK AIR FLOW SENSOR POWER SUPPLY CIRCUIT
• Turn ignition switch on.
• Check supply voltage between air flow sensor ter-
minal 4 and ground in the air flow sensor electrical
connector E-058.
• Battery voltage should exist.
Is the check result normal?
Ye s>>Go to step 5.
No
>>Go to the next step.
4.DETECT MALFUNCTIONING PART
• Check the following:
Harness connectors A-102, E-105
Front fuse and relay box H3
Fuse 22, Fuse 12
Harness open or short between air flow sensor and fuse
Is the check result normal?
Ye s>>Go to the next step.
No
>>Repair or replace malfunctioning parts.
5.CHECK MAF SENSOR REFERENCE VOLTAGE
• Check reference voltage between air flow sensor terminal 7 and ground in the air flow sensor electrical connec-
tor E-058.
• 4.8 - 5.2 V should exist.
Is the check result normal?
Ye s>>Go to step 7.
No
>>Go to the next step.
DIAGNOSIS & TESTING
LTSMD030004
03–478Chery Automobile Co., Ltd.
Page 763 of 1903
Downloaded from www.Manualslib.com manuals search engine 6.CHECK MAF SENSOR REFERENCE CIRCUIT FOR AN OPEN OR SHORT
• Turn ignition switch off.
• Disconnect ECM harness connector.
• Check harness continuity between following terminals.
AIR FLOW SENSOR
TERMINAL ECM TERMINAL
37
4
• Continuity should exist.
• Check harness for short to power or short to ground.
Is the check result normal?
Ye s>>Go to the next step.
No
>>Repair or replace the circuit for an open or short to power or short to ground in harness or connec-
tors.
7.CHECK MAF SENSOR
• Connect air flow sensor connector.
• Connect ECM connector.
• With digital multimeter and the X-431, check sensor signal output data and data stream value.
CAUTION:
To new vehicle (less than 500 km mileage), the sensor output frequency is 10 % higher than stan-
dard value.
CHECK ITEM CHECK CONTENT NORMAL VALUE
Air flow sensor •
Engine coolant
temperature: 80 - 95°C
• Lamp and all other
condition: OFF
• Transaxle: Neutral •
Engine is running
• Warm-up running
• Idle 19-45HZ
• Engine is running: 2,500
RPM 72 - 112 HZ
• Engine is accelerating Frequency direct
proportion with speed
DIAGNOSIS & TESTING
03
03–479Chery Automobile Co., Ltd.
Page 764 of 1903
Downloaded from www.Manualslib.com manuals search engine •Check the sensor signal output data and data stream value.
TERMINAL NO. ITEMCONDITIONDATA (DC VOLTAGE)
19 Air flow sensor •
Engine is running
• Warm-up running
• Idle 0-1V
• Engine is running: 3,000
RPM 6-9V
74 Air flow sensor •
Engine is running
• Warm-up running
• Idle
2.2 - 3.2 V
• Engine is running: 2,500
RPM
Is the check result normal?
Ye s>>Go to step 9.
No
>>Go to the next step.
8.CHECK MAF SENSOR REFERENCE CIRCUIT FOR AN OPEN OR SHORT
• Turn ignition switch off.
• Disconnect ECM harness connector.
• Check harness continuity between following terminals.
AIR FLOW SENSOR
TERMINAL ECM TERMINAL
71
9
• Continuity should exist.
• Check harness for short to power or short to ground.
Is the check result normal?
Ye s>>Go to the next step.
No
>>Repair or replace the circuits for an open or short to power or short to ground in harness or connec-
tors.
DIAGNOSIS & TESTING
03–480Chery Automobile Co., Ltd.
Page 767 of 1903
Downloaded from www.Manualslib.com manuals search engine Check reference values between ECM terminals and ground under the following conditions:
ECM TERMINALNO. ITEM
CONDITION DATA (DC
VOLTAGE)
56 Intake Air
Temperature (IAT) sensor Ignition switch: ON IAT: 0°C
3.2 - 3.8 V
IAT: 20°C 2.3 - 2.9 V
IAT: 40°C 1.5 - 2.1 V
IAT: 80°C 0.4 - 1.0 V
76 Sensor (GND) Ignition switch on 0 V
On Board Diagnostic Logic
• Self-diagnosis detection logic.
DTC NO. DTC DEFINITION DTC DETECTION
CONDITION DTC SET
CONDITION POSSIBLE CAUSE
13 Air temperature
sensor •
Ignition switch ON
position for 60
seconds
• Engine: Running •
Signal output is
over 4.6 V for 4
seconds
continuously
(amount to -45°C
intake air
temperature).
• Signal output is
below 0.2 V for 4
seconds
continuously
(amount to 125°C
intake air
temperature). •
Intake Air
Temperature (IAT)
sensor
• Harness or
connectors
• ECM
DTC Confirmation Procedure:
Before performing the following procedure, confirm that battery voltage is more than 12 V.
• Turn ignition switch off.
• Connect the X-431 scan tool to the Data Link Connector (DLC) - use the most current software available.
• Turn ignition switch on.
• With the scan tool, record and erase stored DTCs in the ECM.
• Start engine and warm it to normal operating temperature, then select view DTC and data stream.
• If the DTC is detected, the DTC condition is current. Go to Diagnostic Procedure - Step 1.
• If the DTC is not detected, the DTC condition is intermittent (See Diagnostic Help and Intermittent DTC Trou-
bleshooting in Section 03 Electronic Engine Controls for more information.
NOTE :
Before performing the following procedure, make sure that the ECM connection is in good condition.
NOTE :
While performing electrical diagnosis & testing, always refer to the electrical schematics for specific circuit
and component information.
DIAGNOSIS & TESTING
03
03–483Chery Automobile Co., Ltd.
