Pedestrian Safety System

[ParaHandy]

The warning has progressed from intermittent to nearly every time the engine runs. Is this a MOT fail, the MOT is due soon?

Douglas

[mike020150]

Presumably, your car is displaying the dash warning about the system which raises the bonnet slightly in the event of a front end crash involving a pedestrian. If so, the first thing to check is that the bonnet is closed fully on both sides. Sometimes the system can be over-sensitive and if the bonnet is not fully closed (even though it may appear to be) the warning can be invoked. The system has a number of sensors which require Jaguar level diagnostics to interrogate them. If one of them is failing, it would be as well to go to a Jaguar dealer or specialist to resolve the matter. It would be better to sort it out before either a crash(!) or it gets to the stage where the car system interprets the signals as the aftermath of a crash and prevents the car from being locked. Without reading the regulations in detail, I suspect that even the latest MoT rules won't have caught up with this technology so it's unlikely to be an MoT failure item, yet. Mike.

[ParaHandy]

Thank you. The main dealer has talked to the people who conduct their MOTs and it is not a failure.

There are 2 sensors throwing out DTC codes; replacing both requires the front bumper to be removed at a total cost approaching £500.

Not having recorded every instance of the warning being given, nevertheless I'm reasonably certain that it never occurs during a journey, only right at the beginning when the engine starts. For no other reason than what's to lose, I charged the battery overnight and the warning has gone - for the time being. I think there is a system timer which prevents any of the more sensitive electronics becoming functional until a few seconds after the engine has started. My fully charged battery drops to 12.2 volts with ignition on and is really quite low with the starter turning. The battery acts as a very good sink, holding the voltage down after the engine has started, and I wonder if recovery is longer than Jag have allowed for particularly as the whole lot gets older?!

Just in passing, the Jag dealers are offering a 3+ Service deal for cars over 3 years old and the prices are competitive. The press release doesn't say that an XK is included but with a little persuasion, they can be.

[mike020150]

Hi Douglas,
That's an interesting development. I think it's the first time that anyone has reported a battery issue flagged by the bonnet warnings alone. Typically, battery voltage issues result in a raft of other warning lamps and window reset problems, i.e. a dashboard full of warning lamps after start-up has become a classic sign of impending battery failure. Mike.