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.

CHECK OTHER DTC OUTPUT (MULTIPLEX COMMUNICATION SYSTEM)

Check if multiplex communication system DTC B1271 is output

Result

RESULT REFERENCE

Result	Proceed to
No output	A
B1271 is output	B

HINT:

DTC B1271 indicates a combination meter communication stop malfunction in the multiplex communication system

B: REPAIR CIRCUIT INDICATED BY OUTPUT CODE (See DTC B1271 COMBINATION METER ECU COMMUNICATION STOP )

A: Go to next step

READ VALUE USING TECHSTREAM (SPEED SIGNAL)

Turn the engine switch off.
Connect the Techstream to the DLC3.
Turn the engine switch on (IG).
Turn the Techstream on.

Check the vehicle speed signal on the Techstream. Enter the following menus Chassis / Tilt & Telescopic / Data List.

Tilt & Telescopic

DATA LIST

Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
Freeze Speed Info	Vehicle speed data/Min 0 km/h (0 mph) Max 255 km/h (158 mph)	Actual vehicle speed	-

Result

RESULT REFERENCE

Result	Proceed to
OK	A
NG (Techstream indication is abnormal)	B
NG (Meter indication is abnormal)	C

HINT

Vehicle speed of 3 km/h (2 mph) or more may be displayed on the Techstream immediately after the vehicle comes to a sudden stop. This is caused by a delay in vehicle signal input via the communication bus and is not a malfunction.

B: REPLACE MULTIPLEX TILT AND TELESCOPIC ECU (See REMOVAL )

C: GO TO METER / GAUGE SYSTEM (See HOW TO PROCEED WITH TROUBLESHOOTING )

A: REPLACE MULTIPLEX TILT AND TELESCOPIC ECU (See REMOVAL )