Toyota Tacoma 2015-2018 Service Manual: Diagnosis System
DIAGNOSIS SYSTEM
1. DESCRIPTION
The 4 wheel drive control ECU records DTCs when the ECU detects a malfunction in the ECU itself or in system circuits.
The DTCs can be read through the DLC3 of the vehicle. When the system seems to be malfunctioning, use the Techstream to check for malfunctions and perform troubleshooting.
2. CHECK DLC3
(a) Inspect the battery voltage.
Standard voltage:
11 to 14 V
If the voltage is below 11 V, recharge the battery before proceeding.
(b) Check the DLC3 (See page .gif)
).
3. FUNCTION OF INDICATOR LIGHT
(a) When a problem occurs in the touch select 2-4 and high-low system, a message is displayed on the multi-information display and/or the 4LO indicator light on the combination meter assembly rapidly blinks* to inform the driver of the problem.
- *: 0.25 second intervals (0.25 seconds on and 0.25 seconds off)
(b) Indicator light status (illumination and blinking) or multi-information display status when DTC is output.
TOUCH SELECT 2-4 AND HIGH-LOW SYSTEM|
DTC No. |
4WD Indicator Light (Green) |
4LO Indicator Light |
Multi-information Display Message |
|---|---|---|---|
|
U0100 |
When 2WD: Not illuminated When H4 or L4: Illuminated |
Rapidly blinking |
- |
|
U0122 |
Not illuminated |
Rapidly blinking*1 |
2WD-4WD mode change malfunction visit your dealer |
|
U0416 |
|||
|
P163B |
|||
|
P17A0 |
|||
|
P17A4 |
Not illuminated |
Not illuminated |
2WD-4WD mode change malfunction visit your dealer |
|
P17A8 |
Not illuminated |
Rapidly blinking |
2WD-4WD mode change malfunction visit your dealer |
|
P17A9 |
|||
|
P17AA |
|||
|
P17AC |
|||
|
P17C7 |
Not illuminated |
When 2WD or H4: Not illuminated When L4: Illuminated |
2WD-4WD mode change malfunction visit your dealer |
|
P17C8 |
|||
|
P2772 |
When 2WD: Not illuminated When H4 or L4: Illuminated |
Rapidly blinking |
- |
|
P279E |
Not illuminated |
Rapidly blinking |
2WD-4WD mode change malfunction visit your dealer |
Rapidly blinking: Blinks at 0.25 second intervals (0.25 seconds on and 0.25 seconds off)
- *1: P163B may also display the 2WD/4WD mode status.
System Diagram
SYSTEM DIAGRAM
Transmitting ECU (Transmitter)
Receiving ECU
Signal
Communication Method
4 wheel drive control ECU
Skid ...
Dtc Check / Clear
DTC CHECK / CLEAR
1. CHECK DTC
(a) Check the DTCs.
(1) Turn the ignition switch off.
(2) Connect the Techstream to the DLC3.
(3) Turn the ignition switch to ON.
(4) Turn the Techstream on.
(5) ...
Other materials:
Open in Stop Light Switch Circuit (C1425)
DESCRIPTION
The skid control ECU (brake actuator assembly) detects the brake operating conditions
through a signal transmitted by the stop light switch.
The skid control ECU incorporates a circuit to detect an open circuit. This DTC
is output when an open circuit is detected in the stop light ...
Brake Switch "A" Signal Compare Failure (P057162)
DESCRIPTION
When the brake pedal is depressed, the stop light switch assembly sends a signal
to the ECM. When the ECM receives this signal, it cancels the dynamic radar cruise
control. The fail-safe function operates to enable normal driving even if there
is a malfunction in the stop light si ...
Communication Malfunction between ECUs Connected by LIN (B2785)
DESCRIPTION
The certification ECU (smart key ECU assembly) monitors communication between
all the ECUs connected to the certification bus lines. When the certification ECU
(smart key ECU assembly) detects errors in communication with all the ECUs connected
to the certification bus lines at a ...