Toyota Tacoma (2015-2018) Service Manual: How To Proceed With Troubleshooting

Toyota Tacoma (2015-2018) Service Manual / Multiplex Communication / Lin Communication System / How To Proceed With Troubleshooting

CAUTION / NOTICE / HINT

HINT:

Use the following procedure to troubleshoot the LIN communication system.
*: Use the Techstream.

PROCEDURE

1.	VEHICLE BROUGHT TO WORKSHOP

2.	CUSTOMER PROBLEM ANALYSIS

In troubleshooting, confirm that the problem symptoms have been accurately identified. Preconceptions should be discarded in order to make an accurate judgment. To clearly understand what the problem symptoms are, it is extremely important to ask the customer about the problem and the conditions at the time the malfunction occurred.
Gather as much information as possible for reference. Past problems that seem unrelated may also help in some cases.

The following 5 items are important points in problem analysis:

What	Vehicle model, system name
When	Date, time, occurrence frequency
Where	Road conditions
Under what conditions?	Driving conditions, weather conditions
How did it happen?	Problem symptoms

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 before proceeding to the next step.

4.	CHECK COMMUNICATION FUNCTION OF LIN COMMUNICATION SYSTEM*

(a) Using the Techstream, inspect the LIN communication function to ensure there are no malfunctions in the communication system.

Click here

Result	Proceed to
DTC is not output	A
DTC is output	B

GO TO DIAGNOSTIC TROUBLE CODE CHART

5.	OVERALL ANALYSIS AND TROUBLESHOOTING*

(a) Terminals of ECU

Click here (b) Data List / Active Test

(b) Data List / Active Test

Click here

6.	REPAIR OR REPLACE

7.	CONFIRMATION TEST

END

System Diagram

SYSTEM DIAGRAM 1. DOOR BUS LINES 2. CERTIFICATION BUS LINES (w/ Smart Key System) ...

Terminals Of Ecu

TERMINALS OF ECU 1. CHECK MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) (a) Disconnect the 1D and 1F driver side junction block connectors. (b) Measure the voltage and resistance according to the va ...

Other materials:

Data List / Active Test
DATA LIST / ACTIVE TEST 1. READ DATA LIST HINT: Using the Techstream to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. This non-intrusive inspection can be very useful because intermittent conditions or sig ...

Dtc Check / Clear
DTC CHECK / CLEAR NOTICE: When the diagnosis system is changed from normal mode to check mode or vice versa, all DTCs and freeze frame data recorded in normal mode are cleared. Before changing modes, always check and make a note of DTCs and freeze frame data. HINT: DTCs which are sto ...

Check For Intermittent Problems
CHECK FOR INTERMITTENT PROBLEMS HINT: Inspect the vehicle ECM using check mode. Intermittent problems are easier to detect with the Techstream when the ECM is in check mode. In check mode, the ECM uses 1 trip detection logic, which is more sensitive to malfunctions than normal mode (default) ...