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DTC B1506: Seat Slide Sensor System Fault 1 (Open in the Seat Slide Sensor Circuit)
DTC B1507: Seat Slide Sensor System Fault Ground Circuit (Short-Circuited to Ground)
DTC B1508: Seat Slide Sensor System Fault Power Supply Circuit (Short-Circuited to Power Supply)
 
 
cautionIf DTC B1506, B1507 or B1508 are set in the SRS-ECU, always diagnose the CAN main bus lines.
 
 
CIRCUIT OPERATION
  • The seat slide sensor sets the current value Hi or Low determined by the seat position.
  • The SRS-ECU determines the seat position according to the current value from the seat slide sensor.
 
 
DTC SET CONDITIONS
The DTC is set when the seat slide sensor output current is not within the specified range.
Cause of trouble for each DTC is as follows.
DTCSYMPTOM
B1506Open circuit in the seat slide sensor or harness
B1507Short to the ground in the seat slide sensor harness
B1508Short to the power supply in the seat slide sensor harness
 
 
TROUBLESHOOTING HINTS
  • Damaged wiring harnesses or connectors
  • Short to ground in the seat slide sensor harness
  • Malfunction of the SRS-ECU
  • Malfunction of the seat slide sensor
 
 
DIAGNOSIS
STEP 1. Using scan tool MB991958, diagnose the CAN bus line.
(1)
cautionTo prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
Connect scan tool MB991958. Refer to "How to connect the scan tool ."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the CAN bus line found to be normal?
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54C, Diagnosis ).
 
STEP 2. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the DTC set?
Go to Step 3 (DTC B1506).
Go to Step 4 (DTC B1507).
Go to Step 5 (DTC B1508).
There is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).
 
STEP 3. Resistance measurement at the SRS-ECU connector and the seat slide sensor connector (DTC B1506).
(1) Check that the negative battery terminal is disconnected. If the negative battery terminal is connected, disconnect it.
(2) While pushing the part "A" indicated in the figure of the harness side connector, turn the lock lever to the direction of the arrow to release the lock lever, and disconnect the SRS-ECU connector.
(3) Disconnect the seat slide sensor connector.
(4)
cautionDo not insert a probe into the terminal from seat slide sensor connector harness side connector front side directly, as the connector contact pressure may be weakened.
Check for continuity between the following terminals. It should be less than 2 ohms.
  • SRS-ECU connector C-124 (terminal No.53) and the seat slide sensor connector D-46 (terminal No.1)
  • SRS-ECU connector C-124 (terminal No.58) and the seat slide sensor connector D-46 (terminal No.2)
Is the check result normal?
go to Step 6.
Repair the harness wires between SRS-ECU connector C-124 and seat slide sensor connector D-46.
 
STEP 4. Check the harness short circuit between seat slide sensor connector D-46 and the SRS-ECU connector C-124 (DTC B1507).
(1) Disconnect the negative battery terminal.
(2) Disconnect the seat slide sensor connector.
(3) While pushing the part "A" indicated in the figure of the harness side connector, turn the lock lever to the direction of the arrow to release the lock lever, and disconnect the SRS-ECU connector.
(4) Measure the continuity between C-124 SRS-ECU connector terminals No.53, 58 and body ground.It should be open circuit.
Is the check result normal?
Go to Step 6.
Repair the harness wires between SRS-ECU connector C-124 and seat slide sensor connector D-46.
 
STEP 5. Check the harness short circuit between seat slide sensor connector D-46 and the SRS-ECU connector C-124 (DTC B1508).
(1) Disconnect the negative battery terminal.
(2) Disconnect the seat slide sensor connector.
(3) While pushing the part "A" indicated in the figure of the harness side connector, turn the lock lever to the direction of the arrow to release the lock lever, and disconnect the SRS-ECU connector.
(4) Connect the negative battery terminal.
(5) Ignition switch: ON.
(6) Measure the voltage between C-124 harness side connector terminals 53, 58 and body ground.Voltage should measure 1 volt or less.
Is the check result normal?
Go to Step 6.
Repair harness wires between the SRS-ECU connector C-124 and seat slide sensor connector D-46.
 
STEP 6. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch to the "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is DTC B1506, B1507 or B1508 set?
Replace the SRS-ECU (Refer to ).
The procedure is complete.