B1506

DTC B1506: Seat Slide Sensor System Fault 1 (Open in the Seat Slide Sensor Circuit)

Seat Slide Sensor Circuit:

CAUTION: If DTC B1506 is set in the SRS-ECU, always diagnose the CAN main bus line.

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
- This DTC is set if there is abnormal resistance between the input terminals of the seat slide sensor. The most likely causes for this code to be set are the followings:
- Open circuit in the seat slide sensor or harness
- Malfunction of connector contact

However, if no DTC reset, the SRS warning light will be switched off (DTC will be retained).

TROUBLESHOOTING HINTS
- Open circuit in the seat slide sensor circuit
- Disengaged seat slide sensor connector
- Improper connector contact
- Malfunction of the SRS-ECU

DIAGNOSIS

Required Special Tools:
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827: MUT-III USB Cable
- MB991910: MUT-III Main Harness A (Vehicles with CAN Communication System)
- MB991865: Dummy resistor
- MB991866: Resister harness

STEP 1. Using scan tool MB991958, diagnose the CAN bus line.

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.




1. Connect scan tool MB991958. Refer to "How to connect the scan tool." Reading Diagnostic Trouble Codes
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.

Q: Is the CAN bus line found to be normal?

YES: Go to Step 2.

NO: Repair the CAN bus line (Refer to Diagnosis). Component Tests and General Diagnostics




STEP 2. 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.

Q: Is the DTC set?

YES: Go to Step 3.

NO: There is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to How to Cope with Intermittent Malfunction).

STEP 3. Check the seat slide sensor. (Using scan tool MB991958, read the diagnostic trouble code.)

1. Disconnect the negative battery terminal.




2. Disconnect the seat slide sensor connector D-27.




3. Connect special tool MB991865 to special tool MB991866.

CAUTION: Do not insert a test probe into the terminal from its front side directly, as the connector contact pressure may be weakened.

4. Insert special tool MB991866 into the D-27 harness side connector by backprobing.
5. Connect the negative battery terminal.
6. Erase the diagnostic trouble code memory, and check the diagnostic trouble code.

Q: Is DTC B1506 set?

YES: Go to Step 4.

NO: Replace the seat slide sensor. Then go to Step 5.

STEP 4. Check the harness for open circuit between SRS-ECU connector C-122 (terminal No.1 and 2) and the seat slide sensor connector D-27 (terminal No.1 and 2).










1. Disconnect SRS-ECU connector C-122 and side-airbag module (RH) connector D-27.

CAUTION: Do not insert a test probe into the terminal from its front side directly, as the connector contact pressure may be weakened.

2. Check for continuity between the following terminals. It should be less than 2 Ohms.
- SRS-ECU connector C-122 (terminal No.2) and the seat slide sensor connector D-27 (terminal No.1)
- SRS-ECU connector C-122 (terminal No.1) and the seat slide sensor connector D-27 (terminal No.2)

Q: Does continuity exist?

YES: Erase the diagnostic trouble code memory, and check the diagnostic trouble code. If DTC B1506 sets, replace the SRS-ECU. Then go to Step 5.

NO: Replace the harness wires between SRS-ECU connector C-122 and seat slide sensor connector D-27. Then go to Step 5.




STEP 5. 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.

Q: Is DTC B1506 set?

YES: Return to Step 1.

NO: The procedure is complete.