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)
18 Upstream oxygen sensor •
Engine is running
• Warm-up condition
• Keep the engine speed
2000 RPM Approximately 0.1 V - 0.9
V (change5-8times in10 seconds periodically)
28 (With EOBD)
4 (Without EOBD) Downstream oxygen
sensor heating --
36 Sensor (GND)•
Warm-up condition
• Idle speed Approximately 0 V
48 (With EOBD)
1 (Without EOBD) Upstream oxygen sensor
heating --
55 Downstream oxygen
sensor •
Engine is running
• Warm-up condition
• Keep the engine speed
2000 RPM Approximately 100 mV
On Board Diagnostic Logic
• Self-diagnosis detection logic.
DTC NO. DTC DEFINITION DTC DETECTION
CONDITION POSSIBLE CAUSE
P0031 O
2sensor 1 heater control
circuit low Engine is running•
Oxygen sensor
• Harness or connectors
(The sensor circuit is open
or shorted)
• 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 select record and erase data stream and DTC.
• Start engine and warm it up to the normal operating temperature.
• Turn ignition switch off and wait at least 10 seconds.
• Start engine and keep the engine speed 2000 RPM for at least 1 minute.
• Let engine idle for 2 minutes.
• With the scan tool, select view DTCs in the ECM.
• If DTC is detected, go to Diagnostic Procedure - Step 1.
• If the DTC is not detected, the DTC condition is intermittent (See Diagnosis & Testing Diagnostic Help in Sec-
tion 03 Electronic Engine Controls).
NOTE :
While performing electrical diagnosis & testing, always refer to the electrical schematics for specific circuit
and component information.
DIAGNOSIS & TESTING
03
03–47Chery Automobile Co., Ltd.
Downloaded from www.Manualslib.com manuals search engine Diagnostic Procedure
1.CHECK GROUND CONNECTIONS
• Turn ignition switch off.
• Loosen and retighten ground screws on the body (See Ground Inspection in Section 03 Electronic Engine Con-
trols).
• Inspect ground connections E-207 and E-208 mounting position (See Vehicle Wiring Harness Layout - Engine
Room Harness (With 1.6L/1.8L Engine) in Section 16 Wiring).
Is ground connections OK?
Ye s>>Go to the next step.
No
>>Repair or replace ground harness or connections.
2.CHECK O2SENSOR ELECTRICAL CONNECTOR
• Disconnect the O
2sensor (1) electrical connector
E-004.
• 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 O2SENSOR HEATER POWER SUPPLY CIRCUIT
• Turn ignition switch on.
• Check supply voltage between O
2sensor terminal
2 and ground in the O
2sensor electrical connector
E-004.
• Battery voltage should exist.
Is the check result normal?
Ye s>>Go to Step 5.
No
>>Go to the next step.
DIAGNOSIS & TESTING
BESM030017
LTSMD030029
03–48Chery Automobile Co., Ltd.