Toyota Tacoma (2015-2018) Service Manual: Diagnosis System

Toyota Tacoma (2015-2018) Service Manual / Engine Immobiliser / Engine Immobiliser System(w/ Smart Key System) / Diagnosis System

DIAGNOSIS SYSTEM

1. DESCRIPTION

(a) The certification ECU (smart key ECU assembly) and ECM control the vehicle engine immobiliser system functions. Engine immobiliser system data and Diagnostic Trouble Codes (DTCs) can be read through the vehicle Data Link Connector 3 (DLC3).

In some cases, a malfunction may be occurring in the engine immobiliser system even though the security indicator light is not illuminated.

When the system seems to be malfunctioning, use the Techstream to check for malfunctions and perform repairs.

2. CHECK DLC3

(a) Check the DLC3 (See page 3. INSPECT BATTERY VOLTAGE ).

3. INSPECT BATTERY VOLTAGE

(a) Measure the battery voltage.

Standard Voltage:

11 to 14 V

If the voltage is below 11 V, recharge or replace the battery.

4. START FUNCTION PROBLEM SYMPTOMS

Symptom	Suspected Area	Component Malfunction	Possible Output DTCs	Related Data List Item
Engine cannot be started*1	Certification ECU (smart key ECU assembly)	Open or short circuit inside ECU	B278A B2799 B279A	Ignition Switch #Codes Immobilizer when IG=ON Immobiliser Master Key Sub Key BCC Malfunction Abnormal Status Different Encrypt Code Different Serial Number Frame Error Response Wireless Starter Com ID Wireless C Code Engine Start Condition ID-BOX Sleep Condition ID-BOX Start Condition Engine Start Request 3bit Code Request L Code Check Unlock Request Receive Lock Request Receive L Code Check (Past) EFI Code Receive EFI communication
	ECM	Open or short circuit inside ECU	B2799 B279A B279C	EFI Code Receive
	SFI system	ECM incompatible with installed engine immobiliser system	B279C	Engine Start Condition EFI Code Receive
Power source mode cannot be changed*1	Engine switch	Open or short circuit inside switch	B278A	Ignition Switch Unlock Request Receive Lock Request Receive
Power source mode cannot be changed*1	Certification ECU (smart key ECU assembly)	Open or short circuit inside ECU	B2271 B2274	Ignition Switch Immobilizer when IG=ON Immobiliser
Steering lock lock/unlock not possible*2	Steering lock ECU (steering lock actuator or upper bracket)	Open or short circuit inside ECU Actuator stuck	B2781 B2782 B2788	Unlock Request Receive Lock Request Receive

*1: Refer to Problem Symptoms Table for Smart Key System (for Start Function).
*2: Refer to Problem Symptoms Table for Steering Lock System.

Registration

REGISTRATION PROCEDURE 1. DESCRIPTION OF CODE REGISTRATION HINT: Registering an ID code enables the entry and start function, wireless door lock control function and engine immobiliser ...

Dtc Check / Clear

DTC CHECK / CLEAR HINT: When using the Techstream with the engine switch off to troubleshoot: Connect the Techstream to the DLC3 and turn a courtesy light switch on and off at 1.5 se ...

Other materials:

Check For Intermittent Problems
CHECK FOR INTERMITTENT PROBLEMS 1. CHECK FOR INTERMITTENT PROBLEMS HINT: A momentary interruption (open circuit) in the connectors and/or wire harnesses between the sensors and ECUs can be detected using the ECU Data List function of the Techstream. (a) Turn the ignition switch off. (b) Con ...

Open in One Side of Bus 2 Branch Line
DESCRIPTION When the CAN bus main lines are normal (no open, short to ground, short to +B or short between lines) and there is an ECU or sensor on the "Communication Bus Check" screen that is indicated as not communicating or whose connection status on the "Communication Bus Ch ...

Data List / Active Test
DATA LIST / ACTIVE TEST 1. ACTIVE TEST HINT: Using the Techstream to perform Active Tests allows relays, VSVs, actuators and other items to be operated without removing any parts. This non-intrusive functional inspection can be very useful because intermittent operation may be discovered befo ...