Chery A15. Manual — part 274

Electronic anti-theft device:
Pay attention not to cut off ECM normal power supply circuit while installing anti-theft
device.
Charcoal canister:
The charcoal canister is controlled by the ECM to adjust the fuel steam volume that goes
into the engine through the charcoal canister so that the fuel will not affect the normal
operation of the engine. The fuel tank evaporation and exhaust control effect is directly
subject to the volume of the charcoal canister. If the canister is too small, the fuel steam
may leak in the case of long-term idle speed or substantial fuel steam production.



Two. Basic checking
Wire harness terminals are reliably fixed;
Fuel circuit and vacuum pipeline are reliably fastened;
Air hose of canister solenoid valve is correctly positioned and securely fastened;
Screw tight the bolts on the oxygen sensor and three-way catalyst and ensure sealing of
fittings; check the exhaust system with 1.3 times atmospheric pressure if necessary to see
if there is any apparent leakage.



Three. System initialization setup
See the section on engine data analysis.

Section Four. Troubleshooting on Electrical Control System

One. Ordinary troubleshooting procedure
Ordinary troubleshooting procedure is as follows:
(1) Troubleshooting description
(2) Confirm customer complaints or fault signs;
(3) Turn on the ignition switch but do not turn on the engine and see if the engine fault
indicator light is on.
(4) Check if the circuit of the engine fault indicator light is normal.
(5) Use diagnostic instrument to see if the engine control module data can be displayed
properly.
(6) Start the engine and see if the engine can start normally.
(7) Is there any troubleshooting code?
(8) Compare the measured values in the data flow displayed on the diagnostic instrument
and the engine diagnostic reference data and see if the measured values are within the
scope;
(9) Check and confirm the troubleshooting code one by one.
(10) Check if the wiring of relevant terminals is proper.
Clear off the troubleshooting code and confirm if the fault is to be repaired or not.



Two. Troubleshooting procedure of apparent intermittent faults
For any apparent intermittent fault, the following steps may be taken to check it up:
1. Initial checking
Before taking the steps, it is necessary to complete ordinary troubleshooting procedure.
The causes can usually be identified with careful observation to reduce the time needed
for troubleshooting. Initial checking procedure is as follows:
(1) Confirm that the grounding parts of the engine control module are clean and properly
fastened;
(2) Check if the vacuum tube and fittings suffer any cracks or leakage;
(3) Check if the throttle body or air inlet suffers any leakage;
(4) Check if the spark plug high-voltage coil is securely fastened (Figure 18-5), make
sure that the wires do not have any crack or fracture and clear away accumulated
charcoals on the spark plug.

(5) Make sure that all terminals and wires are properly connected.

Figure 18-5 Check Spark Plug High-voltage Cable

2. Check according to the troubleshooting flowchart
Thoroughly check according to the troubleshooting flowchart. It is not always necessary
to settle troubles by replacing components.
3. Circuit faults
Most intermittent faults are caused by bad contact of circuits. Check the following
circuits in doubt carefully:

①. Bad contact of wires
②. Bad contact of terminals (Figure 18-6)
③. Damaged terminals
④. Disconnected terminal from circuit

Folded side surrounding terminals

Screw cap

Terminal

Figure 18-6 Terminal Connection

4. Road test
If the cause can’t be identified after careful measurement and checking, a road test may
be carried out. Use a voltmeter to measure all circuits in doubt or use a diagnostic
instrument to measure the fault information of the car. Save the troubleshooting code
after the circuit has been checked.
5. Intermittent engine fault indication
The intermittent lighting up of engine fault indicator light with no troubleshooting code.
The causes include:

①. Ground fault of the ECM

②. Relay is working properly, EMC solenoid valve is actuated or turned on/off to

interfere with the electronic system.

③. Selected electrical equipment is not properly installed, including lights, multi-

channel radio, audio system or anti-theft system.

④. Check the ignition control circuit from ignition system of the spark plug circuit to

the engine successively. The low-voltage circuit between the EMC and the
ignition system shall be well grounded.

⑤. Ground fault of secondary ignition circuit
⑥. Intermittent short circuit of engine fault indicator light or diagnostic terminals

6. Fuel system
Some intermittent faults may be caused by bad quality of fuels. If there is sudden
flameout or other faults during road test, please check if the customer encounters the
following:
(1) Is the car gassed up in the same gas station? If so, there may be fuel quality problems.
(2) Is the fuel purchased in the gas station relatively cheaper? If so, check if there are
sediments, water or other foreign matters in the fuel tank.




Three. Troubleshooting on failure of engine normal startup

①. Circuit – check if the ignition module and spark plug are working normally. Use a

diagnostic instrument to drive Cylinders 1, 4 or Cylinders 2, 3 and test. Check if
the ECM ignition circuit suffers any bad contact.

②. Throttle timing error – throttle collision with piston may be resulted in severe

cases and the cylinder may not obtain the rated compression pressure.

③. Gasoline pressure – check if the gasoline pressure and fuel injection are proper. If

not, check the fuel pump and relay circuit system firstly. A diagnostic instrument
may be used to test if the relay and fuel pump are working properly.

Four. Cleaning of throttle body