B1413
This document has been updated per Mitsubishi TSB# 06-52b-001DTC B1413: Passenger's (Front) Air Bag Module (1st Squib) System Fault for Power Supply Circuit (Short-Circuited to Power Supply)
DTC B1493: Passenger's (Front) Air Bag Module (2nd Squib) System Fault for Power Supply Circuit (Short-Circuited to Power Supply)
Passenger's (Front) Air Bag Module (1st Squid And 2nd Squib) Circuit:
CIRCUIT OPERATION
- The SRS-ECU judges how severe a collision is by detecting signals from the front impact sensors and the front air bag analog G-sensor. If the impact is over a predetermined level, the SRS-ECU outputs an ignition signal. At this time, if the front air bag safing G-sensor is on, the SRS air bag will inflate.
- The ignition signal is input to the air bag module to inflate the air bag.
DTC SET CONDITIONS
This DTC is set if there is abnormal resistance between the input terminals of the passenger's air bag module (squib).
TROUBLESHOOTING HINTS
- Damaged harness wires and connectors
- Short to the power supply in the passenger's air bag module (squib) harness
- Malfunction of the SRS-ECU
DIAGNOSIS
Required Special Tools:
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: MUT-III USB Cable
- MB991910: MUT-III Main Harness A
- MB991865: Dummy resistor
- MB991866: Resister harness
STEP 1. Check the passenger's air bag module. (Using scan tool MB991958, read the diagnostic trouble code.)
1. Disconnect the negative battery terminal.
2. Disconnect the passenger's air bag module connector C-106.
3. Slide the outer housing of the clock spring side of passenger's air bag module connector C-106 in the arrow direction shown, and disconnect the connector.
4. 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.
5. Insert special tool MB991866 into the harness side connector C-106 (terminal No.1 and 2 <1st squib> or terminal No.3 and 4 <2nd squib>) by backprobing.
6. Connect the negative battery terminal.
CAUTION: Always DTC B1491 is set when checking DTC B1413. This is because the second side terminal is isolated when checking it, DTC B1491 is set but this is not a fault. In addition, always DTC B1411 is set when checking DTC B1493 because the first side terminal is isolated.
7. Erase the diagnostic trouble code memory, and check the diagnostic trouble code.
Q: Is DTC B1413 <1st squib> B1493 <2nd squib> set?
YES: Go to Step 2.
NO: Replace the passenger's air bag module. Then go to Step 4.
STEP 2. Check the passenger's air bag module circuit. Measure the voltage at the SRS-ECU connector C-28.
1. Disconnect the negative battery terminal.
2. Disconnect SRS-ECU connector C-28.
3. Disconnect the passenger's air bag module connector C-106.
4. Slide the outer housing of the clock spring side of passenger's air bag module connector C-106 in the arrow direction shown, and disconnect the connector.
5. Turn the ignition switch to the "ON" position.
CAUTION: Do not insert a test probe into the terminal from its front side directly, as the connector contact pressure may be weakened.
6. Measure the voltage between C-28 harness side connector terminals 27 and 28 <1st squib> or 30 and 31 <2nd squib> and body ground. Voltage should measure 0 volt.
Q: Is the measured voltage 0 volt?
YES: Erase the diagnostic trouble code memory, and check the diagnostic trouble code. If DTC B1413 <1st squib> B1493<2nd squib> sets, replace the SRS-ECU. Then go to Step 4.
NO: Go to Step 3.
STEP 3. Check the harness wires for short circuit to power supply between SRS-ECU connector C-28 (terminal No.27 and 28 <1st squib> or terminal No.30 and 31 <2nd squib>) and passenger's air bag module connector C-106 (terminal No.1 and 2 <1st squib> terminal No.4 and 3 <2nd squib>).
Q: Are the harness wires between SRS-ECU connector C-28 (terminal No.27 and 28 <1st squib> or terminal No.30 and 31 <2nd squib>) and passenger's air bag module connector C-106 (terminal No.1 and 2 <1st squib> terminal No.4 and 3 <2nd squib>) in good condition?
YES: Go to Step 4.
NO: Replace the harness wires between SRS-ECU connector C-28 and passenger's air bag module connector C-106. Then go to Step 4.
STEP 4. 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 B1413 <1st squib> B1493 <2nd squib> set?
YES: Return to Step 1.
NO: The procedure is complete.