Code No.B1138 Vehicle speed data fail
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- 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.
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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 13B - Troubleshooting <6B3> or GROUP 13C - Troubleshooting <4N1>). 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 (Refer to ).
Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).