Occupant Classification-ECU
DTC B210D: Battery Voltage LowDTC B210E: Battery Voltage High
Occupant Classification-ECU Power Supply Circuit (Part 1):
Occupant Classification-ECU Power Supply Circuit (Part 2):
CAUTION: If DTC B210D, B210E is set in the occupant classification-ECU, always diagnose the CAN main bus lines.
TROUBLE JUDGMENT
The occupant classification-ECU sets DTC B210D if the power supply fuse voltage decreases to the specified value or less, and sets DTC B210E if the power supply fuse voltage increases to the specified value or more. However, when the status returns to normal, the occupant classification-ECU automatically erases DTCs B210D and B210E.
TECHNICAL DESCRIPTION (COMMENT)
The power supply fuse or the occupant classification-ECU may have a problem.
TROUBLESHOOTING HINTS
- The power supply fuse may be defective.
- The occupant classification-ECU may be defective.
- The battery may be defective.
- The generator may be defective.
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
DIAGNOSIS
Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A (Vehicles with CAN communication system)
STEP 1. Power supply fuse check.
Q: Is the fuse in good condition?
YES: Go to Step 3.
NO: Go to Step 2.
STEP 2. Wiring harness check between the fusible link (34) and the D-39-2 occupant classification-ECU connector terminal No. 21.
- Short circuit check for SRS-ECU power supply wire
Q: Is the check result normal?
YES: Replace the power supply fuse.
NO: Repair the wiring harness. And than replace the power supply fuse.
STEP 3. Battery check.
Refer to Chassis Electrical, Battery Test.
Q: Is the check result normal?
YES: Go to Step 4.
NO: Charge or replace the battery.
STEP 4. Measure the voltage at the ETACS-ECU connector.
1. Disconnect the C-309 ETACS-ECU connector.
2. Measure the voltage between the C-309 harness side connector terminal No. 1 and the body ground.
- The voltage should measure 12 volts (battery positive voltage).
Q: Is the measured voltage approximately 12 volts (battery positive voltage)?
YES: Go to Step 6.
NO: Go to Step 5.
STEP 5. Wiring harness check between the fusible link (34) and the C-309 ETACS-ECU connector terminal No. 1.
- Open circuit check for ETACS-ECU power supply wire
Q: Is the check result normal?
YES: Go to Step 10.
NO: Repair the wiring harness.
STEP 6. Using scan tool MB991958, diagnose the ETACS.
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." Scan Tool Connecting
2. Erase the DTC.
3. Turn the ignition switch to the "ON" position.
4. Check if the DTC is set.
5. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC set?
YES: Diagnose the ETACS (Refer to Chassis Electrical, ETACS, Diagnosis).
NO: Check the input signal of ETACS-ECU ignition switch (IG1) (Refer to Chassis Electrical - ETACS, Symptom procedures). Than go to step 7.
STEP 7. 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." Scan Tool Connecting
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 8.
NO: Repair the CAN bus line (Refer to Controller Area Network, Diagnosis).
STEP 8. 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.
Q: Is the DTC set?
YES: Go to Step 9.
NO: There is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to general (Body and Chassis), How to Cope with Intermittent Malfunction).
STEP 9. Check the harness for open circuit between occupant classification-ECU connector D-39-2 (terminal No.21) and the ETACS-ECU connector C-315 (terminal No.4).
1. Disconnect the negative battery terminal.
2. Disconnect occupant classification-ECU connector D-39-2.
3. Disconnect the ETACS-ECU connector C-315.
4. Check for continuity between the following terminals. It should be less than 2 ohms.
- occupant classification-ECU connector D-39-2 (terminal No.21) and the ETACS-ECU connector C-315 (terminal No.4)
Q: Does continuity exist?
YES: Go to Step 10.
NO: Repair the harness wire between occupant classification-ECU connector D-39-2 and the ETACS-ECU connector C-315.
STEP 10. 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 B210D or B210E set?
YES: Replace the slide adjuster (RH) (Refer to Interior, Front Seat Assembly.
NO: There is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to general (Body and Chassis), How to Cope with Intermittent Malfunction).