— A DENSO fuel pump recall has been expanded to include more than 1.5 million pumps, adding to the 2 million fuel pumps DENSO recalled earlier in 2020.
The low-pressure fuel pump is located in the fuel tank and supplies fuel pressure to the fuel injection system. Inside the pump is an impeller that can crack, deform and cause the fuel pump to fail.
The latest DENSO fuel pump recall includes parts sold to the following automakers.
As in the case of the original DENSO recall, the fuel pump impellers were affected by solvent drying that may have caused surface cracks on the impellers. This can allow the cracked impellers to absorb fuel, deforming the impellers and causing them to make contact with the fuel pumps.
A vehicle will stall at any speed if the fuel pump fails, but an owner may also notice illuminated check engine warning lights and find a vehicle that won't start.
Following the May 2020 recall, DENSO continued to investigate the fuel pump impellers which were manufactured during various periods. The company analyzed the impellers which contain resin, glass fiber and calcium carbonate and found only resin is susceptible to swelling.
"Resin density was found to more closely correlate with the occurrence of field cases than overall impeller density. The resin density findings indicated additional material lots which could contribute to the occurrence of the condition in combination with other factors." - DENSO
DENSO determined a lower minimum surface strength than previously estimated could be possible.
Each car manufacturer will determine which vehicles, if any, should be recalled.