Chery A15. Manual — part 271

High idle speed (slight step down the accelerator pedal to run the engine at a speed of
2000rpm)

Items for checking

1

Engine fault indicator light

Off

2

Is the troubleshooting code
displayed

No

3

Cooling fluid temperature

80 ～ 94

°C

4

Storage battery voltage

13.5 ～ 14.5 V

5 Turning

speed

Actual value (shall be controlled within 2000

±

50 rpm)

6

Ignition advance angle

20 ～ 30

°

7

Fuel injection pulse width

2 ～ 4 mS’

8

Jumping times of the oxygen
sensor within 10 seconds

100 ～ 900 mV /

≥ 10 times

5) Step 5: air conditioning system checking

• Normal idle speed, air conditioning system off

Items for checking

1

Status 3 – A/C system

Appear

2

Status 5 – front evaporator

Appear

• Air conditioner has been turned on and working normally for 10 seconds

Items for checking

1

Engine idle speed

850

± 50 rpm

2

Status 3 – A/C request signal Appear

3

Status 3 – A/C relay

Appear

4

Status 3 – A/C system

Appear

5

Status 4 – Fan 1

Appear

6

Status 5 – Fan 2

Appear

7

Status 5 – front evaporator

Appear

(6) Step 6: driving checking
The following operations must be carried out during driving checkup:
• Throttle opening remains wider than 10% for over 15s;

• Direct gear: when the car is driving at 80km/h, turn off the throttle and slide the car

for over 5s.

Items for checking

1

Engine fault indicator light

Off

2 Troubleshooting

code

No

3

Cooling fluid temperature

80 ～ 94

°C

4

Storage battery voltage

13.5 ～ 14.5 V

5

Air intake manifold absolute
pressure sensor

20 kPa ～ atmospheric pressure

6

Throttle position sensor
working range

0 ～ 99.6%

7 Oxygen

sensor

50 ～ 950 mV

Three. Data analysis and description
Regular checking

• Loosened fittings may result in defected transmission and control of signals;

• The inlet/return oil pipe shall not be wrongly connected; pressure balance vacuum

tube of fuel pressure modulator shall be connected, failing which abnormal
emission and fuel consumption increase may be resulted;

• Charcoal canister cleaning pipeline shall also be connected properly, failing

which abnormal idle speed may be resulted;

• Any bad sealing between the engine cylinder cover and the three-way catalyst

may result in air leakage during engine running to damage the AFR balance and
reduce the transform rate of the three-way catalyst.

Checking of the system and vehicle status
Turn on the key switch but do not run the engine.

• Engine fault indicator light is on, but there shall be no fault;

• Air intake manifold absolute pressure sensor shall display the atmospheric

pressure then;

• Adjust the throttle pull rod and accelerator pedal screws to fully open and close

the throttle;

• When the oxygen sensor is being heated up, the display shall decrease from

450mV; after the heating, the voltage shall be under 200mV;

• The idle speed valve position is determined by the engine temperature; the valve

opening is small during heating while big during cooling.

Turn off the key switch

• If the idle speed control valve is not actuated and ECM power source is not cut off

immediately after the key switch is turned off, check if the ECM normal power

cable is wrongly connected to the ignition switch, which will make it hard for the
engine to restart, cause flameout and influence the exhaust emissions.

Start the engine

• If the engine is not properly started, check if the initialization has been completed

and the fuel circuits are running smoothly and uninterruptedly and check the fuel
system and ignition system components and their connections.

• In the absence of the problems mentioned above, then check the idle speed control

valve and if the instructions take effect on it.

Idle speed checking

• Engine fault indicator light is off and no troubleshooting code is displayed;
• Storage battery voltage shows if the engine is working properly:
Overvoltage indicates engine adjustor fault;
Undervoltage indicates improper engine wiring or engine faults;
• Air intake manifold pressure indicates if there is any leakage and throttle

clearance defect. If the throttle clearance is insufficient, there will be overpressure
and the engine capacity will be affected; in addition, the life spans of the oxygen
sensor and three-way catalyst will be substantially reduced as the throttle opens
too early and the exhaust temperature increases.
Moreover, blocked exhaust system (e.g. foreign matters in the exhaust pipe or
broken three-way catalyst) will also result in overpressure;

• Low position of idle speed motor indicates leakage into the air inlet system; high

position indicates that the throttle body and idle speed control valve are partially
blocked;

• Insufficient jumping of oxygen sensor reading indicates the failure of the oxygen

sensor.

Air conditioning system checking
• The target idle speed will increase by 100rpm when the air conditioner is turned

on and 50rpm when the air conditioner fan is turned on. As they are usually
started simultaneously, the engine idle speed will increase by 150rpm after the air
conditioner is turned on.

Chapter Six. Maintenance and Troubleshooting

Section One. Precautions during Engine Maintenance

1. Preparations for maintenance
Do not maintain the vehicle at a gas station;
Do not maintain the fuel system where there is open fire;
Do not smoke during maintenance


2. Unfix fuel system components (e.g. replace filter, unfix fuel pump or fuel rail
inlet/return pipeline)

Disconnect the storage battery cathode to avoid sparks that would ignite the fuel

steam in the case of short circuit;

Cover the fuel pipe fittings with a piece of cloth and then carefully loosen the fittings

to relieve the fuel pressure;

Avoid spraying the fuel onto the engine and its high-temperature exhaust pipeline;
Keep the fuel off rubber or leather components;
Replace the inlet/return fuel pipe. Gasoline-resistant pipes that can stand a pressure

of over 2MPa must be used.

3. Unfix and maintain components of the electronic control system
The components of the engine management system are relatively reliable. Please check
relevant mechanical components, system fittings, wire harness, ground wire, spark plug
high-voltage terminals and fuel pressure regulator vacuum pipelines, etc first of all when
the vehicle or engine suffers any trouble; repeatedly replace and check before
determining on the damage of electronic injection system components.
In the case of insufficient storage battery voltage or engine fault, do not keep on starting
the engine externally for long, otherwise the three-way catalyst will be damaged;
If maintenance is necessary, turn off the ignition switch or unfix the storage battery
cathode first of all; do not unfix electronic components with power on;
Do not check the system’s electric signals by puncturing the wire harness;
Do not disconnect the storage battery fittings when the engine is running;