B1437

This document has been updated per Mitsubishi TSB# 06-52b-001



DTC B1437: Side Impact Sensor (LH) Power Supply Circuit System

Side Impact Sensor (LH) Circuit:

CIRCUIT OPERATION
The side impact sensor includes an analog G-sensor and CPU, etc. The CPU monitors the analog G-sensor output signal. If the CPU judges that the side-air-bags should be deployed, it sends a fire signal to the SRS-ECU to deploy the side-airbags. Besides that, the CPU diagnoses the internal components of the side impact sensor. If a malfunction occurs, it requests the SRS-ECU to set a diagnostic trouble code.

DTC SET CONDITIONS
This DTC will set when the power supply voltage to the side impact sensor (LH) remains less than a pre-determined value for five seconds.

TROUBLESHOOTING-HINTS
- Damaged wiring harness or connectors
- Malfunction of the side impact sensor (LH) (squib)
- 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

STEP 1. Check the side impact sensor (LH) power supply
circuit at the side impact sensor (LH) connector D-17.

1. Disconnect the negative battery terminal.




2. Disconnect side impact sensor (LH) connector D-17, and measure at the wiring harness side.
3. Connect the negative battery terminal.
4. 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.




5. Measure the voltage between D-17 harness connector terminal 2 and the ground.
A wave pattern of oscilloscope iterates an amplitude of 6 -12 volts.

Q: Is the check result normal?

YES: Replace the side impact sensor (LH). Then go to Step 3.

NO: Go to Step 2.










STEP 2. Check the harness wires for open circuit or short circuit between SRS-ECU connector C-29 (terminal No.19 and 20) and side impact sensor (LH) connector D-17 (terminal No.1 and 2).

NOTE: After inspecting intermediate connector C-128 inspect the wiring harness. If the intermediate connector C-128 is damaged, repair or replace it.

Q: Are the harness wires between SRS-ECU connector C-29 (terminal No.19 and 20) and side impact sensor (LH) connector D-17 (terminal No.1 and 2) in good condition?

YES: Erase the diagnostic trouble code memory, and check the diagnostic trouble code. If DTC B1437 sets, replace the SRS-ECU. Then go to Step 3.

NO: Repair the harness wires between SRS-ECU connector C-29 and side impact sensor (LH) connector D-17. Then go to Step 3.

STEP 3. 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 B1437 set?

YES: Return to Step 1.

NO: The procedure is complete.