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:

Transfer L4 Position Switch Circuit (C1268)
DESCRIPTION A-TRAC is activated if wheel skid is detected while the transfer is in the L4 position. DTC Code DTC Detecting Condition Trouble Areas C1268 L4 detection switch signal input to skid control ECU (master cylinder solenoid ...

Problem Symptoms Table
PROBLEM SYMPTOMS TABLE HINT: Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each sy ...

Pressure Control Solenoid "B" Actuator Stuck Off (P07757F)
SYSTEM DESCRIPTION The ECM uses the vehicle speed signal and signals from the transmission revolution sensors (NT, SP2) to detect the actual gear (1st, 2nd, 3rd, 4th, 5th or 6th gear). The ECM compares the actual gear with the shift schedule in the ECM memory to detect mechanical problems of t ...