Toyota Tacoma (2015-2018) Service Manual: ECM Communication Stop Mode

Toyota Tacoma (2015-2018) Service Manual / Can Communication / Can Communication System / ECM Communication Stop Mode

DESCRIPTION

Detection Item	Symptom	Trouble Area
ECM Communication Stop Mode	Either condition is met: Communication stop for "ECM (Engine)" is indicated on the "Communication Bus Check" screen of the Techstream. Click here Communication system DTCs (DTCs that start with U) that correspond to "ECM Communication Stop Mode" in "DTC Combination Table" are output. Click here	Power source circuit of ECM ECM main line or connector ECM ground circuit ECM

WIRING DIAGRAM

CAUTION / NOTICE / HINT

CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.

NOTICE:

Because the order of diagnosis is important to allow correct diagnosis, make sure to begin troubleshooting using How to Proceed with Troubleshooting when CAN communication system related DTCs are output.
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Before measuring the resistance of the CAN bus, turn the ignition switch off and leave the vehicle for 1 minute or more without operating the key or any switches, or opening or closing the doors. After that, disconnect the cable from the negative (-) battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.
After turning the ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.
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Some parts must be initialized and set when replacing or removing and installing parts.
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After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.
DTC check procedure: Turn the ignition switch to ON and wait for 1 minute or more. Then operate the suspected malfunctioning system and drive the vehicle at 60 km/h (37 mph) or more for 5 minutes or more.
After the repair, perform the CAN bus check and check that all the ECUs and sensors connected to the CAN communication system are displayed as normal.
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Inspect the fuses for circuits related to this system before performing the following procedure.

HINT:

Before disconnecting related connectors for inspection, push in on each connector body to check that the connector is not loose or disconnected.
When a connector is disconnected, check that the terminals and connector body are not cracked, deformed or corroded.

PROCEDURE

1.	SYSTEM CHECK

(a) Check the vehicle specifications.

Result

Result	Proceed to
for 2GR-FKS	A
for 2TR-FE	B

GO TO STEP 4

2.	CHECK FOR OPEN IN CAN BUS LINES (ECM MAIN LINE)

(a) Disconnect the cable from the negative (-) battery terminal.

(b) Disconnect the ECM connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
E13-27 (CANH) - E13-35 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω

Text in Illustration

*a	Front view of wire harness connector (to ECM)

REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (ECM MAIN LINE)

3.	CHECK ECM POWER SOURCE CIRCUIT

(a) Check the ECM power source circuit.

Click here

REPLACE ECM

REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

4.	CHECK FOR OPEN IN CAN BUS LINES (ECM MAIN LINE)

(a) Disconnect the cable from the negative (-) battery terminal.

(b) Disconnect the ECM connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
E20-13 (CANH) - E20-14 (CANL)	Cable disconnected from negative (-) battery terminal	108 to 132 Ω

Text in Illustration

*a	Front view of wire harness connector (to ECM)

REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (ECM MAIN LINE)

5.	CHECK ECM POWER SOURCE CIRCUIT

(a) Check the ECM power source circuit.

Click here

REPLACE ECM

REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

Air Conditioning Amplifier Communication Stop Mode

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Main Body ECU Communication Stop Mode

DESCRIPTION Detection Item Symptom Trouble Area Main Body ECU Communication Stop Mode Either condition is met: Communication ...

Other materials:

FCM Destination Information Uninitialized (C1AAA)
DESCRIPTION When the forward recognition camera is replaced with a new one, the new forward recognition camera attempts to store the country specification information received from the main body ECU (multiplex network body ECU). If the forward recognition camera cannot store the country speci ...

Theft Deterrent System Communication Line High Fixation (B279A,B279A12)
DESCRIPTION If the communication line (EFIO-IMI) to the transponder key ECU assembly is stuck high (e.g. shorted to +B), the ECM stores this DTC. DTC No. DTC Detection Condition Trouble Area DTC Output Confirmation Operation B279A*1 ...

Diagnostic Trouble Code Chart
DIAGNOSTIC TROUBLE CODE CHART If a DTC is displayed during the DTC check, check the parts listed in the table below and proceed to the "See page" given. *1: "Comes on" means the Malfunction Indicator Lamp (MIL) illuminates. *2: "DTC stored" means ...