Toyota Tacoma 2015-2018 Service Manual: Lost Communication with ECM/PCM "A" Missing Message (U010087)

Toyota Tacoma 2015-2018 Service Manual / Ac60e Automatic Transmission / Transaxle / Automatic Transmission System(for 2gr-fks) / Lost Communication with ECM/PCM "A" Missing Message (U010087)

DESCRIPTION

The engine control unit and the transmission control unit are located inside the ECM. The engine control unit intercommunicates with the transmission control unit with the Controller Area Network (CAN).

If there is a problem in this intercommunication, the ECM stores a DTC.

DTC Code	DTC Detection Condition	Trouble Area	SAE
U010087	All conditions are met for 1.25 seconds or more (1-trip detection logic): (A) The ignition switch is ON and battery voltage is 9.5 V or higher. (B) There is no communication between the engine control unit and transmission control unit.	ECM	U0100

DTC Code

DTC Detection Condition

Trouble Area

SAE

U010087

All conditions are met for 1.25 seconds or more (1-trip detection logic):

(A) The ignition switch is ON and battery voltage is 9.5 V or higher.

(B) There is no communication between the engine control unit and transmission control unit.

ECM

U0100

MONITOR STRATEGY

Related DTCs	U0100: Verify communication
Required Sensors/Components (Main)	ECM
Required Sensors/Components (Related)	-
Frequency of Operation	Continuous
Duration	1.25 seconds
MIL Operation	Immediate
Sequence of Operation	None

TYPICAL ENABLING CONDITIONS

Monitor runs whenever following DTCs not stored	None
Battery Voltage	9.5 V or higher
Ignition Switch	ON
Starter	OFF

TYPICAL MALFUNCTION THRESHOLDS

Communication signal

Lost communication with engine control unit

CONFIRMATION DRIVING PATTERN

HINT:

After repairs have been completed, clear the DTCs and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.
When clearing the permanent DTCs, refer to the Clear Permanent DTC procedure (See page ).

Connect the Techstream to the DLC3.
Turn the ignition switch to ON and turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the ignition switch off and wait for 2 minutes or more.
Turn the ignition switch to ON and turn the Techstream on.
Wait for 2 seconds or more with the ignition switch to ON. [*1]
HINT:

[*1] : Normal judgment procedure.

The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.
Enter the following menus: Powertrain / Transmission / Utility / All Readiness.
Input the DTC: U010087.

Check the DTC judgment result.

Techstream Display	Description
NORMAL	DTC judgment completed System normal
ABNORMAL	DTC judgment completed System abnormal
INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
N/A	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

HINT:

If the judgment result shows NORMAL, the system is normal.
If the judgment result shows ABNORMAL, the system has a malfunction.
If the judgment result shows INCOMPLETE or N/A, perform the normal judgment procedure again.

CAUTION / NOTICE / HINT

NOTICE:

Perform the universal trip to clear permanent DTCs (See page ).
Perform registration and/or initialization when parts related to the automatic transmission are replaced (See page )

PROCEDURE

1.	CHECK DTC OUTPUT (IN ADDITION TO DTC U010087)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch ON.

(d) Enter the following menus: Powertrain / Transmission / Trouble Codes.

(e) Read the DTCs using the Techstream.

Result

Result	Proceed to
Only U010087 is output	A
U010087 and other DTCs are output	B

REPLACE ECM

GO TO DTC CHART

Transmission Fluid Temperature Sensor "B" Circuit Short to Battery or Open (P274015)

DESCRIPTION The No. 2 ATF temperature sensor is installed in the transmission valve body assembly. If the ECM detects an abnormally high ATF temperature near this sensor, it illuminates the warn ...

Internal Control Module EEPROM Data Memory Failure (P062F44)

DESCRIPTION The ECM monitors its internal operation and it will set this DTC when it detects an internal malfunction. DTC No. DTC Detection Condition Trouble Area ...

Other materials:

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 ...

Definition Of Terms
DEFINITION OF TERMS Term Definition Monitor Description Description of what the ECM monitors and how it detects malfunctions (monitoring purpose and details). Related DTCs A group of diagnostic trouble codes that are ...

Cursor or Map Rotates when Vehicle Stopped
PROCEDURE 1. CHECK CONDITION (a) Check with the customer if the vehicle has been turned by a turntable. OK: Vehicle has not been turned by a turntable. HINT: If the vehicle is turned on a turntable with the ignition switch ON, the system ...