Geely Diagnosis Flow. Manual part — 76

301

No. 216 Incorrect indication of speedometer

Malfunction Cause

Solution

Speed sensor fails or damaged

1) Lift the vehicle with double props lifter, and shift the gear to
accelerate; view the waveform of the pulse signal from sensor
by oscilloscope; if the pulse signal is disconnected, then the
speed sensor should be replaced;
2) While measuring the voltage between terminals of speed
sensor, place igniting switch to ON and turn the wheel slowly;
the voltage between #1 and #3 terminal of speed sensor
should be varied from 0.5 to 9 V and voltage between #2 and
#3 should be about 8 V; #2 terminal is earthing wire; the
resistance between #2 terminal and body (earth) measured by
Ohm grade of multi-meter is zero, which is in conducting state;
if all the measured values are in normal range, speedometer
sensor should be replaced.

Drive or driven gear of speedometer is
worn out

3) Lift the vehicle with double props lifter, and shift the gear to
accelerate; view the waveform of the pulse signal from sensor
by oscilloscope; if the pulse signal is disconnected or broken
down, then the speedometer should be checked first for
broken sensor; the final driven gear in speed sensor and drive
gear of transmission output shaft should be dismantled and
checked if there is broken tooth; if yes, the gear should be
replaced.

Conducting state or poor contact between
speed sensor connection and instrument
loop

4) Check the cable of speed sensor connection and instrument
loop if there is broken sleeve resulting in short-circuit; if yes,
harness should be repaired or replaced;
5) Remove plugs of speed sensor instrument PCB and
measure their resistance separately with multi-meter; the
resistance between #2 terminal of speed sensor and A9
terminals of instrument plug should be zero as conducting
state; so as the resistance between #3 terminal of speed
sensor and A10 of instrument plug, and between #1 terminal
of speed sensor and A11 of instrument plug;

Fluctuation of power supply for instrument
loop

6) Check the rear connections of instrument panel, please
re-connect or replace if there is loose or poor contact;
Measure voltage of terminal B4 for normal 12V; instrument
connectors B7 and B8 are bond straps; place igniting switch to
ON position, measure the voltage between A10t A9, which
should be about 8V; connector A9 is bond strap and A11 is
signal cable for speedometer.

Malfunction of internal electronic circuit for
speedometer or stuck actuating
mechanism

7) Check PCB of speedometer for signs of sealing-off or
burning. Because the electronic circuit of speedometer
converts the frequency signal from wheel speed sensor to
useful voltage signal to control circuit of speedometer and
drive the motor of odometer, if there is sealing-off or poor
contact, the discontinuous power supply for electronic circuit
will result in unstable speedometer due to irregular swing of
speedometer pointer. Test the combined instrument with
testing bench;
8) Check the internal actuating mechanism of speedometer for
dropping off or check the drive motor and pointer for blocking
by dirt, which may result in blocked or damaged speedometer;
if yes, clean or replace instrument assembly.

Incorrect indication
of speedometer

The types of tyres for front wheels are
different.

Replaced with tyres of same specification as original

302

Lift the vehicle with lifter, and shift the gear to
accelerate the engine; connect oscilloscope to #1
pin of speed sensor to view the waveform of the
pulse signal

Incorrect indication of
speedometer

Measure the voltage between terminals of speed sensor, place
igniting switch to ON and turn the wheel slowly; the voltage
between #1 and #3 terminal of speed sensor should be varied
from 0.5 to 9 V

Check the rear connections of
instrument panel and power supply
of instrument

Check, adjust and
repair

Check if there is conducting state or break
between speed sensor connection and
instrument loop

Repair connection or
replace harness

Check malfunction of internal
electronic circuit for speedometer or
stuck actuating mechanism

Replace instrument
assembly

Check if
speedometer is
damaged

Replace speed
sensor

Replace drive or
driven gear of
speedometer

Check drive or driven
gear of speedometer

Abnormal

Normal

No

Yes

Normal

Abnormal

303

No. 217 Kilometrage on LCD of odometer will accumulate automatically after the engine starts

Malfunction Cause

Solution

Short-circuit of instrument PCB

1) Check PCB of speedometer whether it is burnt or of
short-circuit; because the electronic circuit of
speedometer converts the frequency signal from wheel
speed sensor to useful voltage signal to control circuit of
speedometer and drive the motor of odometer; if the
PCB is short-circuit, will result in discontinuous power
supply for electronic circuit and then affect to
speedometer;
2) Check PCB of instrument for short-circuit due to
soldering sealing-off of dropping-off; if yes, check and
repair or replace instrument assembly;

Short-circuit of odometer drive motor circuit

3) Place igniting switch to ON position, measure with
voltage grade of multi-meter if voltage of odometer drive
motor is in normal range; measure if resistance of drive
motor is in normal range; check if short-circuit of drive
circuit results in abnormal working of odometer motor
and moving of odometer kilometrage; repair drive circuit
or replace drive motor;

Short-circuit of centralized controller

4) Check centralized controller for “always-ON" of A3
speed signal to instrument due to internal short-circuit or
burn-out, which will result in automatic moving of
odometer kilometrage;
5) Switch multi-meter to voltage grade and igniting switch
to ON; connect red probe to A3 terminal of centralized
controller and black probe to bond strap of body; the
voltage measured should be between 0.5 – 9 V; start up
engine and view pointer of multi-meter; there will be no
obvious variation; otherwise, check and repair
centralized controller or replace centralized controller;

Internal short-circuit or damage of ECU for EPS
(Electrical Power-assisted Steering)

6) Besides odometer, the pulse signal from speed sensor
is also provided for centralized controller and EPS, so
the normal working of speedometer will be affected by
damage or short-circuit of any module of them;
7) Firstly, check speedometer under normal working
condition: Lift the vehicle with double props lifter, and
shift the gear to accelerate the engine; view the
waveform of the pulse signal from sensor by
oscilloscope; if speedometer works normally, remove
plugs of speed sensor and centralized controller, start up
engine and view if there is pulse signal on oscilloscope; if
yes, the ECU internal circuit for EPS is broken and
should be replaced.

Wrong connection of harness

Connect the harness again;

Kilometrage on
LCD of odometer
will move
automatically after
start-up of engine

Malfunction of speed sensor

Replace speed sensor

304

Replace
centralized
control module

Kilometrage on LCD of odometer will
accumulate automatically after
start-up of engine

Lift the vehicle with lifter, remove speed
sensor and start up engine; connect
oscilloscope on signal wire (#1 terminal) of
speed sensor and view the signal from
sensor

Check centralized controller; remove plugs of
speed sensor and EPS; switch multi-meter to
voltage grade and igniting switch to ON;
connect red probe to A3 terminal of centralized
controller and black probe to bond strap of
body; measure if there is pulse signal

Check PCB of instrument and
odometer drive motor circuit
for short-circuit due to
soldering sealing-off of
dropping-off

Replace instrument
assembly

Check EPS ECU internal circuit for
short-circuit or break

Replace EPS ECU

Wrong connection of
harness

Malfunction of speed
sensor

Connect the
harness again

Replace speed
sensor

Without signal

Without signal

With signal

With signal