Circuit Fault Diagnosis; Diagnostic Procedure; Diagnostic Tools; Voltmeter And Test Lamp - Changan M201 2014 Wiring Diagram

1.1.3-1

Diagnostic Procedure

Refer to the following procedure for the circuit
fault diagnosis:
1. Confirm Fault
To do the proper repair, confirm the fault
symptoms described by the customer firstly.
Inspect the relevant component carefully to
confirm the fault symptoms and make record.
DO NOT disassemble the component before
confirmation of the fault scope and causes.
2. Read Wiring Diagram and Analyze Causes
Make a complete analysis and judgement on
the fault components from power supply to
grounding according to the sub-system wiring
diagram and determine the repair solution. If
it cannot be determined, please read the
system description in the "Description and
Operation" section in the repair manual to
understand the working principle. And inspect
other circuits that has common part with the
fault circuit, for example, the fuse, grounding,
switch, etc. Inspect the circuit not covered in
step 1. If other components in the common
circuit work properly, it means the fault exists
in its own circuit. Otherwise, the fuse or
grounding may have faults.
3. Inspect Circuits and Components
Always use the wiring diagram together with
repair manual and refer to the diagnostic
procedure for
components in the repair manual. For the
circuit with a control module, fully use
diagnostic tools to do the test. Effective
diagnosis should be a logical and reasonable
operation. Fully
procedures in the repair manual and start the
inspection from the causes with most
possibility and the components with easiest
inspection way.
4. Repair Fault
Repair the fault. Refer to the wiring diagram
and the description for fault treatment in
repair manual. For example, the diagnostic
procedure for poor grounding and the wiring
harness connector treatment.

Circuit Fault Diagnosis

the relevant circuits
use the diagnostic
5. Confirm Circuit Working Condition
After repair, all functions should be reinspected
to confirm the fault repaired. For the fuse blown
fault, Inspect all the relevant circuits using this
fuse.

Diagnostic Tools

1. Voltmeter and Test Lamp

M1103001
Use test lamp or voltmeter to inspect the
circuit status. Test lamp comprises a pair of
wiring harnesses and a 12 V bulb. When
inspecting, connect one wiring harness to the
ground and the other one to the certain
measurement point. If the bulb is lit, it means
the measurement point has power supply.
Warning: DO NOT use test lamp to inspect
the control module voltage. Otherwise it
could damage the interior circuit inside
the control module. Please use a voltmeter
or
with 10 MΩ or higher internal resistance
(for example, to test the ECM voltage).
Voltmeter has the same connection method
as the test lamp, but voltmeter can display the
voltage value of the circuit. Use a voltmeter
with high resistance to test the voltage. If the
circuit has poor connection, the voltmeter
may show the normal value, but the voltage
cannot drive the load successfully.
1.1.3 Circuit Fault
Diagnosis
1.1.3-1
M201 2014.01