FCA US is expanding by an estimated 62,148 vehicles its recall of US-market SUVs to upgrade airbag software.

The action follows a routine review of the originally reported vehicle population by FCA US engineers. There have been no additional incidents and FCA US is “unaware of any related injuries or accidents”.

The campaign will upgrade software that governs side-curtain and seat-mounted side airbags following a small number of inadvertent deployments – most of which occurred in harsh, off-road environments, FCA says. They were prompted by manoeuvres that dramatically changed the vehicles’ angle of operation, relative to the ground, and the airbag systems – sensing potential rollover conditions – automatically activated.

The software upgrade will recalibrate the threshold for FCS deployment and the vehicles will remain compliant with all applicable safety regulations, FCA says.

Affected are certain 2014 and 2015 Jeep Cherokees. The revised estimate for the US totals 230,240. Revised estimates for other markets are as follows: 28,110 in Canada; 6,367 in Mexico and 52,057 outside the NAFTA region. The revised global total is 316,774 – a difference of 68,593.