Thread: Discovery 4 diesel HSE ecu issues

Originally Posted by chiseller

After several days of having flat battery I replaced both(optima and replacement SS thinking problem would be resolved.Wrong. Before battery change I just had to charge the primary battery and starting was not an issue.I was not travelling far enough to keep the battery charged. Once I put the new batteries in nothing. ignition turns on but no starter activity. Connect icarsoft reader and issue is "permanent ECU fault." I live 400+ km from nearest help. Any Gurus who inhabit these pages have any idea what has happened? Have had no issues prior to this.

Easy one first - are you pushing the brake really hard when starting? sometimes, when the brakes are pumped whilst engine off, the pedal goes so hard that it is much more difficult to trigger the brake switch

Assuming that doesn't work, 'Permanent Fault' does sound ominous though - any codes coming up you can share?

Can you use your icarsoft reader to tell the car you've installed a new battery? Gap tool has a specific routine to do that but not sure about your reader.

New brake pedal switch?

Originally Posted by rocket rod

Can you use your icarsoft reader to tell the car you've installed a new battery? Gap tool has a specific routine to do that but not sure about your reader.

My last cranking battery replacement - the indy needed to reset the BMS three times before the car recognised the new battery.
That may be all that's needed.

You really need some codes as a starting point.

As veebs has said make sure your pressing the brake pedal hard enough, as the switch can become faulty and not work with just mild foot pedal.

the bms not detecting a new battery wont prevent the vehicle from starting.

Originally Posted by Redtail

My last cranking battery replacement - the indy needed to reset the BMS three times before the car recognised the new battery.
That may be all that's needed.

Yes I have reset the Bms and has been recognised.

Just a thought, a replacement brake pedal switch is quite cheap on the grand scale of things and fairly easy to replace. Might pay to do it just in case

Before you pulled the batteries out (disconnected), did you ensure the vehicle had gone to sleep?