B15C2

NAVIGATION: NAVIGATION SYSTEM: B15C2: Speed Signal Malfunction
B15C2 - Speed Signal Malfunction

DESCRIPTION

The navigation receiver assembly receives a vehicle speed signal from the combination meter assembly and information from the navigation antenna assembly, and then adjusts vehicle position.

The navigation receiver assembly stores this DTC when the difference between the speed information that the navigation antenna assembly receives and the SPD pulse received from the combination meter assembly becomes large.

HINT
* A voltage of 12 V or 5 V is output from each ECU and then input to the combination meter assembly. The signal is changed to a pulse signal at the transistor in the combination meter assembly. Each ECU controls the respective systems based on the pulse signal.
* If a short occurs in any of the ECUs or in the wire harness connected to an ECU, all systems in the diagram below will not operate normally.





WIRING DIAGRAM

1. for 1AR-FE





2. for 2GR-FE





INSPECTION PROCEDURE

PROCEDURE

1. CHECK VEHICLE SENSOR (OPERATION CHECK)

(a) Enter the "Vehicle Sensors" screen. Refer to Check GPS & Vehicle Sensors in Operation Check Operation Check.





(b) While driving the vehicle, compare the "Speed" indicator to the reading on the speedometer. Check if these readings are almost equal.

HINT
The combination meter assembly receives the vehicle speed signal from the skid control ECU via CAN communication. Therefore, perform the following inspection referring to values on the Data List of the skid control ECU because it is the source of the vehicle speed signal.

OK:

Vehicle speed displayed on the "Vehicle Sensors" screen is almost the same as the actual vehicle speed measured using the Techstream Data List / Active Test.

NG -- INSPECT COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM)

OK -- REPLACE NAVIGATION RECEIVER ASSEMBLY Removal

2. INSPECT COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM)

(a) Check the output waveform.





(1) Remove the combination meter assembly with the connector(s) still connected.

(2) Connect an oscilloscope to terminal E1-9 (+S) and body ground.

(3) Turn the ignition switch to ON.

(4) Turn a wheel slowly.

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





OK:

The waveform is similar to that shown in the illustration.

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

Text in Illustration





NG -- GO TO METER / GAUGE SYSTEM Speed Signal Circuit
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (NAVIGATION RECEIVER ASSEMBLY - COMBINATION METER ASSEMBLY)

(a) Disconnect the E5 navigation receiver assembly connector.

(b) Disconnect the E1 combination meter assembly connector.

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

Standard Resistance:





NG -- CHECK HARNESS AND CONNECTOR (NAVIGATION RECEIVER ASSEMBLY - JUNCTION CONNECTOR)

OK -- REPLACE NAVIGATION RECEIVER ASSEMBLY Removal

4. CHECK HARNESS AND CONNECTOR (NAVIGATION RECEIVER ASSEMBLY - JUNCTION CONNECTOR)

(a) Disconnect the E5 navigation receiver assembly connector.

(b) Disconnect the E24 junction connector.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (NAVIGATION RECEIVER ASSEMBLY - JUNCTION CONNECTOR)

OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (JUNCTION CONNECTOR)