Isuzu Recalls 2025 NRR-EV Trucks Over Risk of Sudden Power Loss

Isuzu Motors Limited has issued a recall for 73 of its 2025 model year NRR-EV trucks due to a defect that may lead to a complete loss of vehicle propulsion. The issue involves a chemical reaction between two types of coolant used in the electric drive motor system, which can lead to system failure and an increased risk of crash. The company is now taking steps to remedy the issue and prevent it in future models.

The defect centers around the use of Valvoline Zerex Dex Cool coolant, which was added to vehicles already containing Valvoline G40 coolant during factory production. According to Isuzu’s investigation, the combination of these coolants may result in the formation of black gel-like debris within the electric vehicle (EV) cooling system. This debris has been found to accumulate on the EV cooling pump shaft, eventually causing the rotor assembly to seize. When the cooling pump fails, the drive motor and inverter temperatures rise, triggering a sequence that reduces power output and can culminate in total loss of propulsion.

Affected vehicles exhibit warning signs that include illumination of warning icons on the instrument cluster and progressively reduced motor torque. The first indication is a red EV system malfunction alert, followed by a turtle icon that signifies the vehicle is about to enter a zero-power state. Isuzu has received eight reports related to this issue but no reports of injuries or crashes have been linked to the defect.

Isuzu identified the issue in late January and after further reports and analysis in February and March, decided on April 1 to initiate a safety recall. The company confirmed that trucks produced in Japan with different coolant specifications have not experienced this problem. Going forward, Isuzu will produce all 2026 models using a compatible Besco Super Type E coolant. A factory stop-ship order was placed in late March to halt the release of affected vehicles.

As part of the remedy, dealers will replace the cooling pump and flush all coolant systems in the affected trucks, replacing them with Besco Type E coolant. If faulty sensor alerts are detected, the level sensors will also be replaced. Updated labels and owner’s manual pages specifying the correct coolant type will be provided to prevent future issues.

Article by multiple RFHC contributors, based upon information from the National Highway Traffic Safety Administration (NHTSA) and Isuzu Motors Limited

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