2UZ-FE ENGINE CONTROL: SFI SYSTEM: DESCRIPTION (2008 Sequoia)

Last Modified: 11-29-2007		1.6 C
Service Category: Engine/Hybrid System	Section: Engine Control
Model Year: 2008	Model: Sequoia	Doc ID: RM000001O2V01TX
Title: 2UZ-FE ENGINE CONTROL: SFI SYSTEM: DESCRIPTION (2008 Sequoia)

DTC

U0101

Lost Communication with TCM

DESCRIPTION

The Transmission Control Module (TCM) and ECM perform 2-way communications with each other via the Controller Area Network (CAN). The TCM sends signals to the ECM concerning required engine rpm, required engine torques, warning indicators in the combination meter, DTCs and other data. The ECM sends signals to the TCM concerning engine rpm, opening angles of the throttle valve, temperature of intake air, temperature of engine coolant, engine torques and other data. If the TCM cannot communicate with the ECM, the TCM will conclude that there is a malfunction in the CAN system, illuminate the MIL and store a DTC.

DTC No.	DTC Detection Condition	Trouble Area
U0101	No communication from TCM continues	Open or short in TCM and ECM circuit TCM ECM

MONITOR STRATEGY

Related DTCs	U0101: Verify communication
Required Sensors/Components (Main)	ECM
Required Sensors/Components (Sub)	-
Frequency of Operation	Continuous
Duration	1.25 seconds
MIL Operation	Immediate
Sequence of Operation	None

TYPICAL ENABLING CONDITIONS

Monitor runs whenever following DTCs are not present	None
Battery voltage	10.5 V or more
Ignition switch	ON
Starter	OFF

TYPICAL MALFUNCTION THRESHOLDS

Communication signal

Lost communication with TCM

INSPECTION PROCEDURE

PROCEDURE

1.	CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC U0101)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

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

(e) Read the DTCs.

Result

Result	Proceed to
U0101 is output	A
U0101 and other DTCs are output	B

2.	REPLACE ECM

(a) Replace the ECM .

3.	CHECK IF DTC RECURS

(a) Connect the Techstream to the DLC3.

(b) Clear the DTC .

(d) Read the DTCs.

Result

Result	Proceed to
No DTC is output	A
Other DTCs are output	B