Code No.B1138
Vehicle speed data fail <Vehicles with 4D5>
caution |
- If diagnosis
code No. B1138 is set, diagnose the CAN bus lines.
- If diagnosis code No. B1138 is set, check whether diagnosis code No. B1156 is also
set.
- When replacing the ECU, always check that the communication circuit is normal.
|
DIAGNOSIS FUNCTION
When the engine-ECU receives invalid or no vehicle speed signal via CAN, the KOS&OSS-ECU
will set diagnosis code No. B1138.
JUDGEMENT CRITERIA
Check Conditions
- The power supply mode is at ON without cranking.
Judgement Criterion
- Any of the following conditions is met, and two seconds or more have elapsed.
- The system does not receive any vehicle speed signal
from the engine-ECU.
- The system receives invalid vehicle speed signal from the engine-ECU.
PROBABLE CAUSES
- Damaged harness wires and connectors
- Malfunction of engine-ECU
- Malfunction of KOS&OSS-ECU
- Malfunction of ASTC-ECU
- Defective vehicle speed sensor
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use the M.U.T.-III to diagnose the CAN bus lines.
Q.
Is the check result normal?
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting
).
STEP 2. M.U.T.-III diagnosis code
Check whether the KOS&OSS-ECU sets diagnosis code No. B1156.
Q.
Is the diagnosis code set?
Refer to Diagnosis code chart.
Go to Step 3.
STEP 3. M.U.T.-III other system diagnosis code
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(1)Check that the vehicle power can be turned ON and engine is started.
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(2)Check the diagnosis code of engine-ECU.
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Q.
Is the diagnosis code set?
Troubleshoot the engine-ECU (Refer to GROUP 13E - Troubleshooting
). Then
go to Step 4.
Go to Step 4.
STEP 4. Check whether the diagnosis code is set again.
Check again if the diagnosis code is set in the KOS&OSS-ECU.
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(1)Erase the diagnosis code.
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(2)Turn the engine switch from "LOCK" (OFF) position to "ON" position.
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(3)On completion, check that the diagnosis code is not set again.
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Q.
Is the diagnosis code set?
Replace the KOS&OSS-ECU and register the chassis number.
Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection
Service Points - How to Cope with Intermittent Malfunction).