4WD Control Switch Circuit
PROCEDURE
CONFIRM PROBLEM SYMPTOM
(a) Confirm the problem symptoms.
ResultResult | Proceed to |
|---|---|
The 4WD indicator light (green) and 4LO indicator light remain off |
A |
The 4WD indicator light (green) remains illuminated, and the 4LO indicator light remains off |
B |
The 4WD indicator light (green) and 4LO indicator light remain illuminated |
C |
| B | ![]() |
GO TO STEP 6 |
| C | ![]() |
GO TO STEP 7 |
|
CHECK 4WD INDICATOR LIGHT (GREEN)
(a) Turn the ignition switch to ON.
(b) for Automatic Transmission:
Move the shift lever to N.
for Manual Transmission:
Depress the clutch pedal.
(c) Turn the transfer position switch to H4.
(d) Wait for 60 seconds.
(e) Check the 4WD indicator light (green).
ResultResult | Proceed to |
|---|---|
The 4WD indicator light (green) blinks*1 or illuminates |
A |
The 4WD indicator light (green) rapidly blinks*2 or remains off |
B |
- *1 (Blinking): Blinks at 0.5 second intervals (0.5 seconds on and 0.5 seconds off)
- *2 (Rapidly blinking): Blinks at 0.25 second intervals (0.25 seconds on and 0.25 seconds off)
| A | ![]() |
END |
|
CHECK FOR DTC
(a) Turn the transfer position switch to L4.
(b) Check if DTC P279E is output after 60 seconds elapse (See page
).
Result | Proceed to |
|---|---|
DTC P279E is not output |
A |
DTC P279E is output |
B |
| B | ![]() |
REPAIR CIRCUIT INDICATED BY OUTPUT CODE |
|
CHECK CAN COMMUNICATION LINE
(a) Select "Bus Check" from the System Selection Menu screen, and follow the prompts on the screen to inspect the CAN Bus (See page
).
OK:
"Bus Check" indicates no malfunctions in CAN communication.
| NG | ![]() |
CHECK CAN COMMUNICATION SYSTEM |
|
CHECK TRANSFER POSITION SWITCH
(a) Remove the transfer position switch with its connector still connected. |
![]() |
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection | Switch Condition | Specified Condition |
|---|---|---|
F15-2 (2-4) - Body ground |
Ignition switch ON 2WD position |
Below 1.5 V |
Ignition switch ON H4 position |
Below 1.5 V |
|
Ignition switch ON L4 position |
10 to 14 V |
|
F15-3 (LO) - Body ground |
Ignition switch ON 2WD position |
10 to 14 V |
Ignition switch ON H4 position |
Below 1.5 V |
|
Ignition switch ON L4 position |
Below 1.5 V |
*a |
Component with harness connected (Transfer Position Switch) |
| OK | ![]() |
CHECK METER / GAUGE SYSTEM |
| NG | ![]() |
REPLACE TRANSFER POSITION SWITCH |
CHECK 4WD INDICATOR LIGHT (GREEN)
(a) Turn the ignition switch to ON.
(b) for Automatic Transmission:
Move the shift lever to N.
for Manual Transmission:
Depress the clutch pedal.
(c) Turn the transfer position switch to 2WD.
(d) Wait for 60 seconds.
(e) Check the 4WD indicator light (green).
ResultResult | Proceed to |
|---|---|
The 4WD indicator light (green) blinks*1 or turns off |
A |
The 4WD indicator light (green) rapidly blinks*2 or remains on |
B |
- *1 (Blinking): Blinks at 0.5 second intervals (0.5 seconds on and 0.5 seconds off)
- *2 (Rapidly blinking): Blinks at 0.25 second intervals (0.25 seconds on and 0.25 seconds off)
| A | ![]() |
END |
| B | ![]() |
GO TO DTC P279E |
CHECK 4LO INDICATOR LIGHT
HINT:
Perform the following procedures with the vehicle stopped.
(a) Turn the ignition switch to ON.
(b) for Automatic Transmission:
Move the shift lever to N.
for Manual Transmission:
Depress the clutch pedal.
(c) Turn the transfer position switch to H4.
(d) Wait for 60 seconds.
(e) Check the 4LO indicator light.
ResultResult | Proceed to |
|---|---|
The 4LO indicator light blinks*1 or turns off |
A |
The 4LO indicator light rapidly blinks*2 or remains on |
B |
- *1 (Blinking): Blinks at 0.5 second intervals (0.5 seconds on and 0.5 seconds off)
- *2 (Rapidly blinking): Blinks at 0.25 second intervals (0.25 seconds on and 0.25 seconds off)
| A | ![]() |
END |
|
CHECK FOR DTC
(a) Turn the transfer position switch to 2WD.
(b) Check if DTC P279E is output after 60 seconds elapse (See page
).
Result | Proceed to |
|---|---|
DTC P279E is not output |
A |
DTC P279E is output |
B |
| B | ![]() |
REPAIR CIRCUIT INDICATED BY OUTPUT CODE |
|
CHECK TRANSFER POSITION SWITCH
(a) Remove the transfer position switch with its connector still connected. |
![]() |
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
Tester Connection | Switch Condition | Specified Condition |
|---|---|---|
F15-2 (2-4) - Body ground |
Ignition switch ON 2WD position |
Below 1.5 V |
Ignition switch ON H4 position |
Below 1.5 V |
|
Ignition switch ON L4 position |
10 to 14 V |
|
F15-3 (LO) - Body ground |
Ignition switch ON 2WD position |
10 to 14 V |
Ignition switch ON H4 position |
Below 1.5 V |
|
Ignition switch ON L4 position |
Below 1.5 V |
*a |
Component with harness connected (Transfer Position Switch) |
| OK | ![]() |
CHECK CAN COMMUNICATION SYSTEM |
| NG | ![]() |
REPLACE TRANSFER POSITION SWITCH |
Test yourself
A quick Toyota Tacoma quiz: every answer comes with an explanation and a link to the manual page.
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