Inspection Procedure

WARNING: This page is about a different car, the 2008 Lexus IS F. However, it is still accessible from the selected car via links, so may be relevant.

PERFORM ACTIVE TEST USING TECHSTREAM (TACHO METER OPERATION)

Connect the Techstream to the DLC3.
Turn the engine switch on (IG).
Turn the Techstream on
Enter the following menus" Body Electrical / Combination Meter / Active Test.

Check the operation by referring to the values in the table below.

Combination Meter

DIAGNOSTIC NOTE

Tester Display	Test Part	Control Range	Diagnostic Note
Tacho Meter Operation	Tachometer	0,1000, 2000, 3000, 4000, 5000, 6000, 7000 (rpm)	Confirm that the vehicle is stopped, engine idling

OK: Tachometer indication is normal.

NG: REPLACE COMBINATION METER (See REMOVAL )

OK: Go to next step

READ VALUE USING TECHSTREAM (ENGINE RPM)

Connect the Techstream to the DLC3
Engine start
Turn the Techstream on
Enter the following menus. Body Electrical / Combination Meter / Data List

Check the values by referring to the values in the table below.

Combination Meter

DIAGNOSTIC NOTE

Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
Engine Rpm	Engine speed/Min 0 rpm, Max 12750 rpm	Almost same as actual engine speed (tachometer indication)	If data received from the ECM exceeds the range that can be displayed on the meter, the meter continues to display the maximum value of the range

Result

RESULT CHART

Result	Proceed to
The tachometer indication differs from the engine speed displayed on the Techstream.	A
Engine speed displayed on the Techstream is almost the same as the tachometer indication	B
Both the tachometer indication and the engine speed displayed on the Techstream are 0.	C

B: Go to step 3

C: Go to step 4

A: REPLACE COMBINATION METER (See REMOVAL )

READ VALUE USING TECHSTREAM (ENGINE SPEED)

Connect the Techstream to the DLC3
Engine start
Turn the Techstream on
Enter the following menus: Powertrain / Engine and ECT / Data List.

Check the values by referring to the table below

Engine and ECT

DIAGNOSTIC NOTE

Tester Display	Measurement item/Range	Normal Condition	Diagnostic Note
Engine Speed	Engine speed/Min 0 rpm, Max 16383 75 rpm	Almost same as actual engine speed (tachometer indication)	-

OK: Engine speed displayed on the Techstream is almost the same as the tachometer indication.

NG: GO TO SFI SYSTEM (for 2UR-GSE) (See DIAGNOSTIC TROUBLE CODE CHART )

OK: Go to next step

CHECK HARNESS AND CONNECTOR (COMBINATION METER - ECM)

Disconnect the A6 and J34 connectors

Measure the resistance according to the value(s) in the table below

Standard Resistance

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Condition	Specified Condition
A6-15 (TACH) - J34-16 (S)	Always	Below 1 Ω
A6-15 (TACH) - Body ground	Always	10 kΩ or higher

Fig 1: Identifying Harness And Connector (Combination Meter - ECM)

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step

INSPECT ECM (INPUT WAVEFORM)

Check the input signal waveform

Reconnect the J34 connector
Reconnect the A6 ECM connector
Connect the oscilloscope to the terminal J34-16 (S) and body ground.
Start the engine

Check the signal waveform according to the condition(s) in the table below

ITEM CONDITION CHART

Item	Condition
Tool setting	5 V/DIV, 10 ms /DIV
Vehicle condition	Engine idling

OK: The waveform is displayed as shown in the illustration.

HINT:

When the system is functioning normally, one engine revolution generates 4 pulses. As the engine speed increases, the width indicated by (A) in the illustration narrows.

Fig 2: Inspecting ECM (Input Waveform)

NG: REPLACE ECM (for 2UR-GSE) (See REMOVAL )

OK: REPLACE COMBINATION METER (See REMOVAL )