ALL MODE 4X4 SYSTEM
TF-17
C
E
F
G
H
I
J
K
L
MA
B
TF
Engine speed signal T R R R
Engine coolant temperature signal TR
Accelerator pedal position signal T R R
Output shaft revolution signal R T
A/C compressor feedback signal TR
Vehicle speed signalTRR
RT
ABS warning lamp signal T R
Brake warning lamp signal T R
SLIP indicator lamp signal T R
ESP OFF indicator lamp signal T R
4WD warning lamp signalTR
4WD mode indicator lamp signalTR
Parking brake switch signalRT
MI signal TR
Steering angle sensor signal R T
Engine and A/T integratedTR
RT
A/T self-diagnosis signal R TSignals ECM TCMESP/TCS/
ABS control
unitSteering
angle sensor4WD control
unitCombination
meter
TF-18
TROUBLE DIAGNOSIS
TROUBLE DIAGNOSISPFP:00004
Fail-safe FunctionEDS001VE
If any malfunction occurs in 4WD electrical system, and control unit detects the malfunction, 4WD warning
lamp on combination meter turns ON to indicate system malfunction.
When 4WD warning lamp is ON, vehicle changes to front-wheel drive or shifting driving force-4WD (Rear-
wheels still have some driving torque).
How to Perform Trouble DiagnosisEDS001VF
BASIC CONCEPT
To perform trouble diagnosis, it is the most important to have understanding about vehicle systems (con-
trol and mechanism) thoroughly.
It is also important to clarify customer complaints before inspec-
tion.
First of all, reproduce symptoms, and understand them fully.
Ask customer about his/her complaints carefully. In some cases,
it will be necessary to check symptoms by driving vehicle with
customer.
CAUTION:
Customers are not professional. It is dangerous to make an
easy guess like "maybe the customer means that...," or
"maybe the customer mentions this symptom".
It is essential to check symptoms right from the beginning in
order to repair malfunctions completely.
For intermittent malfunctions, reproduce symptoms based on
interview with customer and past examples. Do not perform
inspection on ad hoc basis. Most intermittent malfunctions are
caused by poor contacts. In this case, it will be effective to shake
suspected harness or connector by hand. When repairing with-
out any symptom diagnosis, you cannot judge if malfunctions
have actually been eliminated.
After completing diagnosis, always erase diagnostic memory.
Refer to TF-31, "
How to Erase Self-diagnostic Results" .
For intermittent malfunctions, move harness or harness connec-
tor by hand. Then check for poor contact or reproduced open circuit.
SEF233G
SEF234G