Suzuki Wagon R Plus RB310 Service Manual page 334

Troubleshooting
Step
1 Check Evaporator Temp. Sensor
1) Disconnect connectors from ECM with igni-
tion switch turned OFF.
2) Check for proper connection to "E21-15"
and "E22-28" wire terminals of ECM con-
nector.
3) If OK, measure resistance between "E21-
15" and "E22-28" wire terminals of ECM
connector. (See Fig. 1.)
At 0°C: 6.3 – 6.9 k
At 25°C: 1.8 – 2.2 k
Is it within specification?
2 Check A/C signal
1) Measure voltage between "E21-30" terminal
of ECM connector and vehicle body ground
under the following condition.
With ignition switch ON and A/C switch
OFF: 10 – 14 V
With ignition switch ON, A/C and heater
blower switch ON: 0 – 1 V
Is check result as specified?
3 Check A/C signal
1) Connect connectors to ECM with ignition
switch turned OFF.
2) Measure voltage between "E21-30" wire ter-
minal of ECM connector and vehicle body
ground under the following condition.
With ignition switch ON and A/C switch
OFF: 10 – 14 V
With ignition switch ON, A/C and heater
blower switch ON: 0 – 1 V
Is check result as specified?
4 Check Radiator Fan Control System
Is radiator cooling fan started when A/C and
heater blower switch turned ON?
5 Check Radiator Fan Control Circuit
1) Check DTC with scan tool.
Is DTC P0480 displayed?
6 Check Radiator Cooling Fan
1) Check radiator cooling fan referring to
"Radiator Cooling Fan Inspection" in Sec-
tion 6B2.
Is check result satisfactory?
7 Check A/C Compressor Control System
Is A/C compressor started when A/C and
heater blower switch turned ON while engine
running?
ENGINE GENERAL INFORMATION AND DIAGNOSIS (M13 ENGINE) 6-2-159
Action
Ω
Ω
Yes
Go to Step 2.
Go to Step 3.
Go to Step 4.
Go to Step 7.
Go to "DTC P0480 Fan 1
(Radiator Cooling Fan)
Control Circuit" in this
section.
Radiator cooling fan drive
circuit malfunction.
If circuit OK, go to Step 7.
A/C system is in good
condition.
No
Faulty A/C evaporator
temperature sensor or its
circuit.
A/C and heater blower
switch circuit, A/C refriger-
ant pressure switch or
heater controller malfunc-
tion.
Poor "E21-30" terminal
connection.
If OK, substitute a known-
good ECM and recheck.
Go to Step 5.
Go to Step 6.
Replace radiator cooling
fan motor.
Go to Step 8.