Chery Tiggo 2009 Service Manual page 686

Check reference values between ECM terminals and ground under the following conditions:
ECM TERMINAL
NO.
69
On Board Diagnostic Logic
• Self-diagnosis detection logic.
DTC NO.
P0645
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.
• Turn A/C switch on, 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.
402
03–
DIAGNOSIS & TESTING
ITEM
• After engine is started for 5 seconds, A/C
can be turned on.
• If IAT above 140.3 , A/C will be shut off.
• If ECT is above 140.3°C, A/C will be shut
off. If ECT is below 111.8°C, A/C will be
resume.
• If A/C high pressure is above 20 bar, A/C
Air Condition (A/C) will be shut off. If A/C high pressure is
relay control signal below 19.5 bar, A/C will be resume.
• If evaporator temperature is below 1.5°C,
A/C will be shut off. If evaporator
temperature is above 4.5°C, A/C will be
resume.
• If system voltage is below 8.04 V, A/C will
be shut off. If system voltage is above
10.01 V, A/C will be resume.
DTC DETECTION
DTC DEFINITION
A/C clutch relay
Engine is running
circuit
CONDITION
CONDITION CONDITION
ECM detected that
the input signal is
acceptable range.
DATA (AVERAGE
DC VOLTAGE)
0 V or 12 V
DTC SET
POSSIBLE CAUSE
• Fuse
• A/C relay
• Harness or
out of the
connectors
• ECM
Chery Automobile Co., Ltd.