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

Toyota Tacoma (2015-2018) Service Manual / Cruise Control / Cruise Control System(for 2gr-fks) / Diagnosis System

DIAGNOSIS SYSTEM

1. DESCRIPTION

The ECM stores DTCs (Diagnostic Trouble Codes) when trouble occurs on the vehicle. The diagnosis system allows reading of DTCs stored in the ECM when a the Techstream is connected to the DLC3 (Data Link Connector 3). If the CRUISE MAIN indicator light does not come on after a DTC check, it means that a malfunction has occurred in the cruise control system. Use a the Techstream or SST to check for DTCs.

2. CHECK DLC3

(a) The ECM uses ISO 9141-2 for data communication. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 9141-2 format.

Terminal No.	Tester Connection	Condition	Specification
4	Chassis ground - Body Ground	Always	Below 1 Ω
16	Battery positive - Body Ground	Always	9 to 14 V

HINT:

If the Techstream display shows "UNABLE TO CONNECT TO VEHICLE" after connecting the Techstream to the DLC3 and turning the ignition to the ON position, there is a problem in either the vehicle or the Techstream itself.

If communication is normal when connecting the tester to another vehicle, inspect the DLC3 on the original vehicle.
If communication is still not possible when connecting the tester to another vehicle, it suggests the problem exists in the tester. In this case, consult the Service Department listed in the tester's instruction manual.

3. CHECK INDICATOR

(a) Turn the ignition switch to the ON position.

Text in Illustration

*1	Cruise Control Indicator Light

(b) Check that the CRUISE MAIN indicator light comes on when the cruise control main switch ON-OFF button is pushed on, and that the indicator light goes off when the ON-OFF button is pushed off.

HINT:

If there is a problem with the ON/OFF illumination of the indicator light, inspect the cruise main indicator light circuit (See page ).

HINT:

If a malfunction occurs in the vehicle speed sensor, stop light switch assembly or other related parts while cruise control driving, the ECM actuates AUTO CANCEL of the cruise control. Then the power indicator turn off, the warning light illuminates and the vehicle display indicates a malfunction, to inform the driver of the malfunction. At the same time, data of the malfunction is stored as a diagnostic trouble code (DTC).

Road Test

ROAD TEST HINT: 'SET' and '-', 'RES' and '+', 'ON-OFF' functions share the same switch. Operate the cruise control main switch according to the directions i ...

Terminals Of Ecu

TERMINALS OF ECU 1. ECM Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition E14-20 (TC) - ...

Other materials:

LVDS Signal Malfunction (from Extension Module) (B1532)
DESCRIPTION The stereo component tuner assembly and the radio and display receiver assembly are connected by an LVDS communication line. This DTC is stored when an LVDS communication error occurs between the stereo component tuner assembly and the radio and display receiver assembly. ...

Open in Occupant Classification ECU Battery Positive Line (B1794)
DESCRIPTION DTC B1794 is set when a malfunction is detected in the occupant detection ECU. DTC No. DTC Detections Conditions Trouble Areas B1794 Occupant detection ECU circuit malfunction Occupant detection ECU malfuncti ...

Components
COMPONENTS ILLUSTRATION *1 COWL TOP VENTILATOR LOUVER SUB-ASSEMBLY *2 FRONT FENDER UPPER PROTECTOR LH *3 FRONT FENDER UPPER PROTECTOR RH *4 FRONT WIPER ARM HEAD CAP *5 WINDSH ...