Downloaded from www.Manualslib.com manuals search engine •Continuity should not exist.
Is the check result normal?
Ye s>>Go to the next step.
No
>>Repair or replace circuit for short to ground in harness or connectors.
11 .CHECK INJECTOR RESISTANCE
• Disconnect injector harness connectors (See Fuel Pressure Test in Section 04 Fuel Delivery).
• Check the resistance of the injectors.
INJECTOR
NO. INJECTOR
TERMINAL RESISTANCE
(APPROXIMATELY) (20°C)
11&2
16
21&2
31&2
41&2
Is the check result normal?
Ye s>>Go to the next step.
No
>>Replace injector.
Go to step 13.
12.CHECK INJECTOR
WARNING!
Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
• Remove fuel delivery rail with injectors (See Fuel Injector Rail Removal & Installation 1.6L & 1.8L & 2.0L in
Section 04 Fuel Delivery).
NOTE :
Be careful not to drop the fuel injectors when removing the fuel delivery rail.
• Keep fuel hose and all injectors connected to injector rail.
• Disconnect all injector harness connectors.
• Disconnect all ignition coil harness connectors.
• Prepare pans or saucers under each injector.
• Crank engine for about 3 seconds.
• Make sure fuel does not drip from injector.
Is the check result normal?
Ye s>>Go to next step.
No
>>Replace the injectors from which fuel is dripping. Always replace O-ring with new one.
DIAGNOSIS & TESTING
03–140Chery Automobile Co., Ltd.
Downloaded from www.Manualslib.com manuals search engine ON-VEHICLE SERVICE
Engine Coolant Temperature (ECT) Sensor
Description
The Engine Coolant Temperature (ECT) sensor threads into the coolant outlet connector. The ECT is a negative
thermal coefficient sensor.
Operation
The ECT provides an input to the Engine Control Module (ECM). As temperature increases, resistance of the sensor
decreases. As coolant temperature varies, the ECT sensor resistance changes resulting in a different voltage value
at the ECT sensor signal circuit. The ECM uses the input to control air-fuel mixture, timing, A/C compressor and
radiator fan on/off times.
Removal & Installation
1. Disconnect the negative battery cable.
2. Drain the cooling system (See Cooling System Draining Procedure in Section 06 Cooling System).
WARNING!
Never remove the pressure relief cap under any conditions while the engine is operating or hot. Failure to follow
these instructions could result in personal injury or damage to the cooling system or engine. To avoid having
scalding hot coolant or steam blow out of the cooling system, use extreme care when removing the pressure
relief cap. Wait until the engine has cooled, then wrap a thick cloth around the pressure relief cap and turn it
slowly one turn (counterclockwise). Step back while the pressure is released from the cooling system. When you
are certain all the pressure has been released, (with a cloth) turn and remove the pressure relief cap. Failure to
follow these instructions may result in serious personal injury.
3. Disconnect the coolant temperature sensor electri-cal connector.
CAUTION:
Remove the coolant temperature sensor when
the engine is cold.
4. Remove the engine coolant temperature sensor(1).
(Tighten: Engine coolant temperature sensor to 20
N·m)
5. Discard the O-ring.
LTSM030035
03
03–217Chery Automobile Co., Ltd.
Downloaded from www.Manualslib.com manuals search engine GENERAL INFORMATION
Description
The Engine Control Module (ECM) utilizes integrated circuitry and information carried on the Controller Area Network
(CAN) data bus along with many hard wired inputs to monitor many sensors and switches inputs throughout the
vehicle. In response to those inputs, the internal circuitry and programming of the ECM allow it to control and inte-
grate many electronic functions and features of the vehicle through both hard wired outputs and the transmission of
electronic message outputs to other electronic modules in the vehicle over the CAN data bus.
The following are the input and output components monitored by the ECM. The monitored functions include compo-
nents from the engine, ignition, transaxle, air conditioning, or any other ECM supported subsystem.
ECM Inputs
•Brake Switch Sensor
• A/C Pressure Switch
• Camshaft Position (CMP) Sensor
• Crankshaft Position (CKP) Sensor
• Engine Coolant Temperature (ECT) Sensor
• Intake Air Temperature (IAT) Sensor
• Air Flow Sensor
• Throttle Position Sensor (integral with Electronic Throttle Control Actuator)
• Power Steering Switch
• Accelerator Pedal Position (APP) Sensor
• Knock Sensor
• Oxygen Sensor (Upstream & Downstream)
• Clutch Pedal Switch (manual transaxle only)
ECM Outputs
• Canister Control Valve
• Fuel Injectors
• Fuel Pump Relay
• Electronic Throttle Control Actuator
• Ignition Coil
• A/C Compressor
• Cooling Fan
• Oxygen Sensor heating coil (Upstream & Downstream)
Operation
The ECM monitors components and circuits and tests them in various ways depending on the hardware, function,
and type of signal. For example, analog inputs such as throttle position or engine coolant temperature are typically
checked for opens, shorts and out-of-range values. This type of monitoring is carried out continuously. Some digital
inputs like vehicle speed or crankshaft position rely on rationality checks - checking to see if the input value makes
sense at the current engine operating conditions. These types of tests may require monitoring several components
and can only be carried out under appropriate test conditions.
The ECM is a pre-programmed, microprocessor-based digital computer. It regulates ignition timing, air-fuel ratio,
emission control devices, charging system, certain transmission features, speed control, air conditioning compressor
clutch engagement and idle speed. The ECM can adapt its programming to meet changing operating conditions.
03
03–229Chery Automobile Co., Ltd.
Downloaded from www.Manualslib.com manuals search engine Compression Gauge
Fuel Pressure Gauge
GENERAL INFORMATION
03
03–233Chery Automobile Co., Ltd.
Downloaded from www.Manualslib.com manuals search engine ECM Connector Pin-Out Table
ECM PIN-OUT TABLE
PINCIRCUIT IDENTIFICATION PINCIRCUIT IDENTIFICATION
1 (With EOBD)
42Intake Air Temperature Sensor
Upstream Oxygen Sensor Heater (Without
EOBD)
2 Ignition Coil 2 43-
3 GND (Ignition) 44Switched Supply Voltage
4 (With EOBD)
45Switched Supply Voltage
Downstream Oxygen Sensor Heater
(Without EOBD)
5 Ignition Coil 1 46Canister Control Valve
6 Injector 2 47Injector 4
7 Injector 3 48Upstream Oxygen Sensor Heater (With
EOBD)
(Without EOBD)
8 Engine Speed Output 49-
9 Coolant Temperature Output 50Fan Relay Control
10 Fuel Consumption Output 51GND (Signal)
11 EPC Lamp 52-
12 Continuous Supply Voltage 53GND (Signal)
13 Ignition Switch 54 Electronic Throttle Control Actuator
14 EMS Relay (Main Relay) 55Downstream Oxygen Sensor
15 Crankshaft Position Sensor 56-
16 Accelerator Position Sensor 57-
17 Sensor (GND) 58Brake Switch
18 Upstream Oxygen Sensor 59-
19 Knock Sensor 1 60A/C Middle Pressure Switch
20 Knock Sensor 2 61GND (Power)
21 Brake Switch 62CAN-H
22 -63Switched Supply Voltage
23 Accelerator Sensor 64 Electronic Throttle Control Actuator
24 -65 Electronic Throttle Control Actuator
25 -66 Electronic Throttle Control Actuator
26 -67 Electronic Throttle Control Actuator
27 Injector 1 68Fan Relay Control 2
28 Downstream Oxygen Sensor Heater (With
EOBD) 69Air Compressor Relay
(Without EOBD)
29 -70Fuel Pump Relay
30 -71Diagnostic Link K
31 MIL Lamp 72-
32 Regulated Sensor Supply 3 73Regulated Sensor Supply 2
33 Regulated Sensor Supply 1 74-
34 Crankshaft Position Sensor 75A/C Stand By
GENERAL INFORMATION
03
03–245Chery Automobile Co., Ltd.
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)
6 Injector 2
•Engine is running
• Warm-up condition
• Idle
• Accelerate suddenly Voltage: 11 - 14 V
7
Injector 3
27 Injector 1
47 Injector 4
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: 1.88 V 0V
33 Regulated sensor supply 1 Approximately 5 V
37 Air flow sensor Approximately 322 kg/h
Approximately 1.39 V
On Board Diagnostic Logic
• Self-diagnosis detection logic.
DTC NO. DTC DEFINITION DTC DETECTION
CONDITION DTC SET
CONDITION POSSIBLE CAUSE
P0171 Fuel trim system too
lean Engine is running The amount of
mixture ratio
compensation is too
large (The mixture
ratio is too lean). •
Intake air leaks
• Air flow sensor
• Fuel injector
• Exhaust gas leaks
• Incorrect fuel
pressure
• lack of fuel
• Incorrect PCV
hose connection
• Upstream O
2sensor
•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.
DIAGNOSIS & TESTING
03
03–329Chery Automobile Co., Ltd.
Downloaded from www.Manualslib.com manuals search engine 7.CHECK FUEL PRESSURE
• Release fuel pressure to zero.
• Install fuel pressure gauge (2) and check fuel
pressure.
• Observe the following fuel pressures when testing (See Fuel Pressure Test in Section 04 Fuel Delivery).
FUEL PRESSURES
Key On 400 kPa (4.0 bar)
Key Off 380 kPa (3.8 bar) in 10 minutes
Engine Idle 400 kPa (4.0 bar )
- 420 kPa (4.2 bar)
Is the check result normal?
Ye s>>Go to step 9.
No
>>Go to the next step.
8.DETECT MALFUNCTIONING PART
• Check the following:
Fuel pump and circuit.
Fuel pressure regulator.
Fuel lines.
Fuel filter for clogging.
Is the check result normal?
Ye s>>If with the X-431, go to the next step.
If without the X-431, go to step 10.
No
>>Repair or Replace malfunctioning part.
DIAGNOSIS & TESTING
BESM030020
03–332Chery Automobile Co., Ltd.
Downloaded from www.Manualslib.com manuals search engine 12.CHECK INJECTOR RESISTANCE
• Disconnect injector harness connectors (See Fuel Pressure Test in Section 04 Fuel Delivery).
• Check the resistance of the injectors.
INJECTOR
NO. INJECTOR
TERMINAL RESISTANCE
(APPROXIMATELY) (20°C)
1 1&2
16
2 1&2
3 1&2
4
1&2
Is the check result normal?
Ye s>>Go to the next step.
No
>>Replace injector.
Go to step 14.
13.CHECK INJECTOR
• Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
• Remove fuel delivery rail with injectors (See Fuel Injector Rail Removal & Installation 1.6L/1.8L/2.0L in Section
04 Fuel Delivery).
NOTE :
Be careful not to drop the fuel injectors when removing the fuel delivery rail.
• Keep fuel hose and all injectors connected to injector rail.
• Disconnect all ignition coil harness connectors.
• Prepare pans or saucers under each injector.
• Crank engine for about 3 seconds.
• Fuel should be sprayed evenly for each injector.
Is the check result normal?
Ye s>>Go to next step.
No
>>Clean or replace the defective fuel injector.
14.CHECK DTC
• With the X-431 scan tool, read ECM DTCs.
• See DTC Confirmation Procedure.
Is DTC P0171 still present?
Ye s>>Replace the ECM.
NOTE : The Immobilizer control module must be matched to the new ECM (See ECM Removal & Instal-
lation in Section 03 Electronic Engine Controls).
No
>>The system is now operating properly.
Reassemble the vehicle and road test to verify the customers complaint is repaired.
DIAGNOSIS & TESTING
03
03–335Chery Automobile Co., Ltd.