Airbag control unit with part number 98820-2X300

What is the function of the airbag control unit 98820-2X300?

The airbag control unit with part number 98820-2X300 is the central safety module in the Nissan Terrano WD21 (1985–1995). It continuously monitors data from crash sensors, controls the entire restraint system, and ensures precise deployment of the airbags in the event of an accident.

As an airbag control module or SRS ECU (Supplemental Restraint System – Electronic Control Unit), it serves as the brain of the passive safety system. It processes signals from acceleration sensors to assess the severity of a collision and, if necessary, activates the airbags and seatbelt pretensioners.

This control unit is also compatible with related part numbers 285001478 and 0-285-001-478, which are treated as technically equivalent units in professional workshops and provide the same core functionality in the vehicle.

Why does the control unit 98820-2X300 fail?

The most common cause of failure for the 98820-2X300 control unit is the storage of crash data after an accident, which locks the unit. Other defects arise from moisture damage to the electronics, general component aging, or unsuccessful prior repair attempts.

Following airbag deployment, so‑called crash data—or “hard codes”—are stored in the control unit’s internal memory. These data cannot be erased using standard diagnostic tools and permanently disable the module’s functionality, even if all external components of the airbag system have been replaced.

Ingress of moisture is another critical issue. It causes corrosion on the circuit board and can lead to short circuits or failure of sensitive electronic components such as processors or memory chips. Additionally, natural component aging over time may also result in malfunctions.

How do you recognize a fault in the 98820-2X300?

A typical defect of the 98820-2X300 control unit manifests as a permanently illuminated airbag warning light on the instrument cluster. Often, the control unit can no longer be read by diagnostic equipment (no communication), or error codes remain stored that cannot be cleared.

The most obvious sign is the persistently lit airbag warning light, which does not turn off even after the engine starts. This indicates a serious fault in the safety system and results in failure during the mandatory technical inspection.

Another clear symptom is when the workshop’s diagnostic tool cannot establish communication with the airbag control unit. The module no longer responds to queries, preventing accurate fault analysis.

After an accident, crash data remains stored, making reactivation of the system impossible. Similarly, internal errors may appear as non‑erasable error codes in the memory, for example, related to side airbags.

It is recommended to have the control unit inspected at a specialized workshop before removal to determine whether the fault stems from external components such as defective sensors, cables, or connectors.

In which vehicles is the 98820-2X300 control unit installed?

The airbag control unit with part number 98820-2X300 is specifically designed for the Nissan Terrano model series WD21, produced between 1985 and 1995. It serves as the primary control unit for the restraint system in this vehicle model.

At Airbag24, we repair the 98820-2X300 control unit for the following model:

Nissan Terrano WD21 (model years 1985–1995)

Although this part number is occasionally mentioned in connection with the successor model, the Nissan Terrano II (up to 2006), its confirmed application range is limited to the WD21 series. Therefore, a careful verification of the part number on the removed unit is essential.

How does the repair of the 98820-2X300 proceed at Airbag24?

Professional repair at Airbag24 includes sending in the removed control unit, conducting a detailed electronic analysis, selectively erasing crash data, and resetting internal faults. Following a successful functional test, the device is returned fully operational with a 12-month warranty.

Once the control unit arrives at Airbag24, technicians perform a comprehensive incoming inspection. They verify communication and read out the fault memory to confirm the symptoms reported by the customer.

The core of the repair lies in restoring the original functionality. This involves securely erasing stored crash data at the chip level and resetting internal errors (“hard codes”), ensuring the unit operates like new again.

If a defect was caused by moisture or aging components, the affected parts on the circuit board are professionally replaced. The control unit is then subjected to a functional test to ensure it operates flawlessly. We provide a 12-month warranty on every repair.

What shipping options does Airbag24 offer?

You can either ship your control unit to Airbag24 free of charge yourself or arrange a convenient UPS pickup. For returns, we offer free standard UPS shipping as well as faster express and cash-on-delivery options. Personal collection is also available.

For sending your unit to us, you have two choices: you can mail the defective control unit yourself or use our pickup service, where UPS collects the package directly from your location.

Following successful repair, return shipping is provided free of charge via standard UPS delivery by default.

If you prefer faster delivery or other payment methods, additional options include UPS express shipping, standard UPS shipping with cash-on-delivery, and UPS express shipping with cash-on-delivery.

You may also, by prior arrangement, pick up your repaired control unit in person at our premises.