Autonomous braking triggered by roadside guardrail on Suzuki’s pint-sized 4WD

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Suzuki says it won’t stop deliveries of its highly anticipated Jimny four-wheel-drive – but is considering a software update – after overseas tests found a glitch that caused the car to repeatedly slam the brakes even though there was no obstacle. Testing in the US found the Suzuki Jimny’s stability control could be triggered after the autonomous emergency braking system detected a guardrail when rounding a bend. It is believed the Suzuki Jimny mistook the guardrail for another vehicle and repeatedly applied the brakes with force, as our video shows (above). The condition occurred on some other bends on the winding mountain pass but the intervention was most aggressive on this particular corner in the hills near Pasadena, on the outskirts of Los Angeles. The fault occurred with such regularity on this particular stretch of road that this video was taken on the third pass after being triggered on two prior attempts.

The glitch was discovered during a round of World Car of the Year testing in November ahead of the LA Auto Show, where 48 journalists from around the globe evaluated 38 contenders for the 2019 award. Suzuki Japan had air-freighted two identical left-hand-drive Jimny 4WDs from Germany because the model is not sold in the US. It was also an opportunity for media from other countries where the Jimny is not sold to sample the car. Suzuki Japan had sent Jimny chief engineer Hiroyuki Yonezawa and two supporting engineers to accompany the two vehicles for the test drive program. The glitch was detected on one of the Suzuki Jimnys on the first of five days of testing – but after being advised of the incident, engineers initially could not replicate the fault.

However, the same fault occurred on the second Suzuki Jimny later in the test drive program – and this time the incident was captured on video and shown to senior Suzuki representatives. The chief engineer relayed the information and forwarded the video to head office in Japan, but Suzuki could not replicate the issue at its test course there. Suzuki then sent two more engineers to the US who were able to replicate the incident in the same conditions on the same road depicted in the video – using the two Jimny test cars that had been made available for media test drives. A statement released via Suzuki Australia boss Michael Pachota said the “continuous activation” of stability control occurred “when a specific road condition, tilt angle in the road, incline and slope, and degree of the curve was combined with a certain level of speed”.

The statement continued: “There is a possibility that the (stability control) is instantaneously switched on (by) reacting to the vehicle sway when departing the S-shaped curve -- and then consecutively switches on because the vehicle is circling the curve at high speeds.” The video shows the vehicle travelling between 70km/h and 90km/h through the curve. Suzuki added: “The intervention of the stability control may give a sense of discomfort to the driver but is not an event that would disturb the vehicle’s direction of movement.” However, in the test captured on video the steering wheel initially jolts after the stability control is applied abruptly. Contrary to how it seems at first glance, the stability control activation was not caused by a sudden turn of the steering wheel. The video also shows the stability control system applied the brakes repeatedly even when the steering wheel was eventually able to be held steady through the bend.

Suzuki says there are no plans to stop delivery of the Jimny but Japan is evaluating whether a software or calibration change may be required. Suzuki Australia says the Jimny due on sale locally from late January 2019 has the same autonomous emergency braking detection system as the example tested in Los Angeles that experienced the glitch. The only difference is that the version of the Jimny exported to Germany gains speed sign recognition, but this does not impact the autonomous emergency braking or stability control systems – and there were no speed signs near the test curve. A statement from Suzuki said the company will “further analyse the event and carefully consider how to adjust the program while maintaining the Jimny’s performance balance”.

“Therefore,” Suzuki responded, “we regret to say we are unable to inform you when exactly we will be able to implement any changes to the program at the moment.” In September, the Suzuki Jimny earned three stars out of five for safety by European NCAP. In that test Euro NCAP noted the Jimny’s autonomous emergency braking system (AEB) “performed well in tests of its functionality at the low speeds, typical of city driving, at which many whiplash injuries are caused”. However, Euro NCAP noted, “the Jimny did not qualify for these points as Euro NCAP requires good head restraint performance as a prerequisite for AEB points”. The first shipments of the first new Suzuki Jimny in 20 years are already on the water and heading our way. Pricing will be released in late January ahead of their Australian showroom arrival in early February.