Downloaded from www.Manualslib.com manuals search engine Check reference values between ECM terminals and ground under the following conditions:
ECM TERMINAL NO.ITEMCONDITIONDATA (AVERAGE DC
VOLTAGE)
17 Sensor (GND)•
Engine is running
• Warm-up condition:
78°C
• Idle: 795 RPM
• IAT: 36°C
• IAT signal voltage: 1.88
V Approximately 0 V
33 Regulated sensor supply 1 5 V
37 Air flow sensor Approximately 322 kg/h
Approximately 1.39 V
73 Regulated sensor supply 1 5 V
On Board Diagnostic Logic
• Self-diagnosis detection logic.
DTC NO. DTC DEFINITION DTC DETECTION
CONDITION DTC SET
CONDITION POSSIBLE CAUSE
P0102 Mass or Volume Air
Flow (MAF) circuit
low input Ignition switch on or
engine is runningECM detected that
the input signal is
out of the
acceptable range.•
MAF sensor
• Intake air leaks
• 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.
• 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 :
While performing electrical diagnosis & testing, always refer to the electrical schematics for specific circuit
and component information.
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 connections.
DIAGNOSIS & TESTING
03–58Chery Automobile Co., Ltd.