HAIMA 7 Service Manual(MT)-U Heater and air conditioning system

Troubleshooting
Step Inspection Action
*5 Inspect continuity of wiring harness between
fuse block and front climate control unit.
• Turn ignition switch to on position.
• Turn both a/c switch and fan switch on.
• Remove airflow mode cable and air mix
cable, remove the front climate unit.
• Measure voltage at front climate control
unit connector terminal b (ig2 signal).
• Is voltage approximately equivalent to b+
(positive battery voltage)?
*6 Inspect continuity of wiring harness between
front climate control unit and resistor.
• Turn ignition switch to on position.
• Turn off front fan switch.
• Measure voltage at front climate control
unit terminal f (blower fan signal).
• Is voltage approximately equivalent to b+
(positive battery voltage)?
*7 Verify whether malfunction is in wiring
harness (front climate control unit is
grounded) or front climate control unit.
• Turn ignition switch to lock position.
• Is front climate control unit terminal d (gnd
signal) grounded?
8 Inspect for dtcs of pcm.
• Check the dtcs in on-board diagnostic
system (engine control).
• Is there any dtc displayed?
Yes
No
Yes
No
Yes
No
Yes
No
Go to next step.
Repair wiring harness between fuse
block and front climate control unit, go
to step 28.
Go to next step.
Inspect wiring harness between front
climate control unit and resistor, then go
to step 28.
Replace front climate control unit, then
go to step 28.
Repair wiring harness between fuse
block and a/c relay, then go to step 28.
Go to appropriate inspection procedure.
(the cause may be a/c input signal cut-off
of pcm)
Go to next step.
*9 Verify whether malfunction is in
electromagnetic cultch system or elsewhere.
• Remove a/c relay.
• Turn ignition switch to on position.
• When a/c relay connector terminals c short
circuit with d (on wire harness side), does
electromagnetic clutch operate?
Yes
Go to next step.
No Go to step 24.
U-38