Mitsubishi L400 Space Gear airbag control unit repair

What is a Mitsubishi L400 Space Gear airbag control unit?

The airbag control unit is the central control unit of the restraint system (SRS) in the Mitsubishi L400 Space Gear. It monitors the system continuously, evaluates the signals from the crash sensors in an accident and decides within milliseconds which airbags and seatbelt pretensioners deploy.

Every time you switch on the ignition, the control unit runs a self-test. The airbag warning light comes on briefly and goes out if everything is in order. If it stays on or flashes, the control unit has detected a fault in the system and reports it this way.

The control unit is installed in the Mitsubishi L400 Space Gear (1994 to 2005). If the system deploys in an accident, it stores crash data and locks itself. The unit is then mechanically undamaged, but still reports a fault and must be tested and repaired.

Why is the Mitsubishi L400 Space Gear airbag control unit defective?

Most often the control unit locks itself after an accident because crash data is stored, even if no airbag has deployed. Other causes are aged electronic components, cold solder joints, moisture and corrosion on connectors, and voltage spikes.

The stored crash data cannot be removed with an ordinary diagnostic tool. Regardless of any accident, electronic components age, and cold solder joints lead to intermittent contacts. If moisture gets in, the contacts of the connectors corrode. Voltage spikes, for example from a weak battery or jump-starting, also put stress on the control unit.

Watch for these signs: the airbag warning light stays on permanently, the fault memory cannot be cleared, or the diagnostic tool cannot connect to the control unit.

Common error codes for Mitsubishi L400 Space Gear airbag control unit repair

The error codes for the Mitsubishi L400 Space Gear relate to internal control unit faults, communication over the data bus, the power supply and the deployment of the system. Which code is in the fault memory depends on the defect.

These codes are frequently read out during this repair:

• B1498 → Internal control unit fault in memory
• B1496 → Internal control unit fault in data memory
• B1646 → Control unit configuration data does not match
• B1699 → Collective deployment detected by control unit
• U0001 → Data bus (CAN) failed
• U0154 → Communication timeout with occupant detection
• B1476 → Ignition supply voltage drops impermissibly

Error codes are read out with a diagnostic tool. A single code does not prove that the control unit is defective, because connectors, wiring or an airbag module can also be the cause. The test provides clarity.

What part numbers are available for the Mitsubishi L400 Space Gear airbag control unit repair?

The part number is on the label of the control unit and determines the exact version. Within a model series there are different numbers depending on equipment and year of manufacture.

We know of these numbers for the Mitsubishi L400 Space Gear; the list makes no claim to completeness:

• MR277718
• MR277719

Compare the number on your unit with the list. This only ensures that it is the right unit. Whether it is defective is only shown by reading out the fault memory or by the test.

The way to a repair: have the fault memory read out, disconnect the battery and remove the control unit. Create a repair order online and send in the unit. Processing at Airbag24 usually takes 3–4 working days and covers testing, repairing and testing again.

The repaired control unit comes back with all vehicle data and is ready for use as soon as it is refitted — no coding or programming is required.