Chery A15. Manual — part 118

The thermo-sensitive resistance is made of a kind of semiconducting material with negative
temperature coefficient, where its resistance will sharply decrease as the temperature
increases.

5. FUEL METER

The operation of the fuel meter is basically the same as the water temperature meter. It is also
the cross coil type of indicator needle meter. See figure below (Illustration-5)—the fuel meter
is located at right of the figure.

Fuel meter (Illustration-5)

When the float is moving along with the fuel level in the fuel tank, the sliding contact linked
with the float staff will respond accordingly so as to change the value of the thick-film
resistance. When the fuel tank is full, the value of the thick-film resistance will be the
minimum and the current of the cross coil will be the maximum. The indicator needle of the
fuel meter points at the maximum scale F. On the contrary, when the fuel in the tank is
exhausted, the value of thick-film resistance will be the maximum, and the indicator needle
deflexion value of the fuel meter points being the minimum scale E.

The relationship between fuel quantity and resistance is indicated in the table below.

The relationship between fuel quantity and resistance

Float position

Capacity (L)

Resistance (Ω)

Empty

0

283

Half full

30

89

Full 55 36

FAULT DIAGNOSIS AND TROUBLESHOOTING

T-29

Components

Malfunction

symptoms

Malfunction

reasons

Malfunction diagnosis

and troubleshooting

Remarks

The

speedometer

does not

function or

have an

excessive

error.

The

speedometer

does not

function or

there is a large

error between

the indicated

speed and the

actual speed.

(1) The Hall
Speed Sensor of
speedometer.
(2) The indicator
needle of
speedometer is
jammed.
(3) Output shaft
driving gear of
gearbox is
seriously worn
out or the gear’s
engagement
clearance is
excessive.
(4) The
speedometer is
damaged.
(5) The engine is
damaged.
(6) The
connecting circuit
is faulty.

(1) If the speedometer does
not function, firstly inspect
the engagement of Hall
Speed Sensor and the drive
gear to verify that there is
any malfunction. If
everything is normal, then
remove and inspect the
speedometer.
(2) In the case of only
inaccurate indication
malfunction, it is caused
usually by the damage of
the interior part of the
meter.
(3) Inspect the link
between the speed signal
and the ECU, and the
signal wire between engine
and instrument.

The water

temperature

meter does

not function.

The indicator

needle of

water

temperature

meter does

not function

after engine

starting.

(1) The water
temperature meter
is damaged.
(2) The water
temperature
sensor is
ineffective.
(3) The circuit of
water temperature
meter is open.
(4) The voltage
regulator is
damaged.
(5) The ECU is
damaged.

(1) Open the engine bonnet
and pull out the connector
of the water temperature
sensor. Inspect whether the
resistance of water
temperature sensor is
normal; if it is normal,
inspect the signal from
sensor to the ECU, and
signal from the ECU to
instrument.
(2) If the above circuits are
normal, connect it to the
connector of combination
instrument and turn on the
ignition switch. Inspect to
see whether voltage
appears at the yellow/red
wires of water temperature
sensor connector. If
voltage appears, it
indicates that the water
temperature sensor is
damaged; if there is no
voltage, it indicates that

T-30

water temperature meter or
voltage regulator is faulty.
(3) Remove the instrument
panel and maintain the
normal connection of the
wiring harness. Connect a
multimeter between the
output terminal 1 of
voltage regulator positive
grid and the grounding
terminal 2 to measure the
voltage. If the voltage is
higher than 10.5V or lower
than 9.5V, it indicates that
the voltage regulator is
faulty; Otherwise it
indicates that water
temperature meter is faulty
itself.

The fuel

meter does

not function

The indicator

needle does

not move after

ignition

switch is

turned on.

(1) The fuel meter
is damaged.
(2) The fuel meter
sensor is
ineffective.
(3) The circuit of
fuel meter is
open.
(4) The voltage
regulator is
damaged.
(5) There is no
fuel in the fuel
tank.

(1)Verify that there is
gasoline in the tank.
(2)Turn on the ignition
switch and verify that the
water temperature gauge
functions properly. If the
water temperature gauge
functions properly, it
indicates that the voltage
regulator of the combined
instrumentation functions
properly.
(3) Disconnect the plug of
the sensor of the fuel
meter, inspect with
multimeter that there is
electricity in the
purple/black wire, and then
inspect the grounds of the
brown wire and the body.
If there is electricity in the
purple/ black wire and the
brown wire is normal,
which indicates that there
is malfunction in the fuel
meter sensor, and it must
be replaced.
(4) If there is no electricity
in the purple/black wire,
then verify that the circuit
between purple/black wire

See

circuitry

diagram of

the fuel

meter

T-31

of the plug of the fuel
meter sensor, and the 21#
socket of the connector of
the combined
instrumentation is open,
the route of the circuit is:
purple /black wire of the
plug of the fuel meter
sensor→ the 3# socket of
the connector M of the
relay plate → the #12
socket of the connect U1
of the relay plate → the
brown wire → the #21
socket of the connector of
the combined
instrumentation.
(5) If the circuit is on and
the brown wire is normal,
then there is malfunction
in the fuel meter.

Oil warning

lamp always

on

The warning

lamp for

engine oil

pressure is

always on

while driving.

(1) Malfunction
of low pressure
switch (30KPa
switch).
(2) Low pressure
switch circuit is
short.
(3) Malfunction
of high pressure
switch (180kPa
switch).
(4) High-pressure
switch circuit is
open.
(5) Pressure in the
lubricating oil
circulation can
not reach the
specified
requirement.

Firstly identify whether the

lubricating system or

warning system is faulty.
This is normally done by

measuring the oil pressure

to diagnose the

malfunction.

(1) When connecting the
positive grid of the battery
and the low-pressure
switch with a diode testing
light, the latter will be
lighted. Start up the engine
and increase the speed
slowly. When the pressure
reaches 15-45KPa, the
diode-testing light should
be off. Otherwise it
indicates that the
low-pressure switch is
faulty; run the engine at
idle speed, with oil
pressure higher than
45KPa, the light-emitting
diode should be off. If the
pressure is lower than
15KPa, it indicates that the
lubricating system is
faulty.

T-1

T-1

T-1

T-32