Subaru Legacy 2005 Service Manual page 4089

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
Step
1 CHECK CRUISE CONTROL COMMAND
SWITCH.
1) Remove the driver's airbag module. <Ref.
to AB-16, REMOVAL, Driver's Airbag Module.>
2) Disconnect the harness connector of cruise
control command switch.
3) Turn the ignition switch to ON.
4) Measure the voltage between harness con-
nector terminal and chassis ground.
Connector & terminal
(ST3) No. 1 (+) — Chassis ground (
(ST3) No. 3 (+) — Chassis ground (
2 INSPECTION FOR CANCEL SWITCH.
1) Turn the ignition switch to OFF.
2) Remove the cruise control command
switch. <Ref. to CC-5, REMOVAL, Cruise Con-
trol Command Switch.>
3) Measure the resistance between switch ter-
minals when CANCEL switch is pressed and
not pressed.
Terminals
No. 2 — No. 3:
3 CHECK SET/COAST SWITCH.
Measure the resistance between switch termi-
nals when SET/COAST switch is pressed and
not pressed.
Terminals
No. 2 — No. 3:
4 CHECK RESUME/ACCEL SWITCH CIRCUIT.
Measure the resistance between switch termi-
nals when RESUME/ACCEL switch is pressed
and not pressed.
Terminals
No. 2 — No. 3:
CRUISE CONTROL SYSTEM (DIAGNOSTICS)
Check
Is the voltage more than 5 V?
−
):
−
):
Is the resistance less than 1 Ω
when CANCEL switch is
pressed? Is the resistance
approx. 4 kΩ when CANCEL
switch is not pressed?
Is the resistance approx. 250 Ω
when SET/COAST switch is
pressed? Is the resistance
approx. 4 kΩ when SET/
COAST switch is not pressed?
Is the resistance approx. 1500
Ω when RESUME/ACCEL
switch is pressed? Is the resis-
tance approx. 4 kΩ when
RESUME/ACCEL switch is not
pressed?
CC(diag)-17
Yes
Go to step 2. Check the harness
for open or short
circuit between
cruise control
command switch
and ECM.
Go to step 3. Replace the cruise
control command
switch. <Ref. to
CC-5, Cruise Con-
trol Command
Switch.>
Go to step 4. Replace the cruise
control command
switch. <Ref. to
CC-5, Cruise Con-
trol Command
Switch.>
Replace the ECM. Replace the cruise
<Ref. to FU(H4SO control command
2.0)-34, Engine switch. <Ref. to
Control Module CC-5, Cruise Con-
(ECM).> <Ref. to trol Command
FU(H4SO 2.5)-37, Switch.>
Engine Control
Module (ECM).>
<Ref. to
FU(H4DOTC)-34,
Engine Control
Module (ECM).>
<Ref. to
FU(H6DO)-34,
Engine Control
Module (ECM).>
No