Brake Pedal Force to Start Car

key76 · Jul 13th, 2020, 21:23

Not driving my car much these days and noticed that after it’s been sat for a while the brake pedal goes rock hard. That’s fine, my Merc used to do the same. However the sensor for detecting my foot on pedal to allow me to start car must be way down the travel or the pedal because I have to proper force the pedal to get the car to allow me to start it.

Is this normal? Feels wrong. The Merc used to make pedal rock hard, but would always start with very little pressure required on pedal.

gregg · Jul 13th, 2020, 21:50

I’ve had exactly the same for the last month or so on my V90 T5 2018, although I’ve been using mine every day. Will be interested also if anyone has an answer..

dingov70 · Jul 13th, 2020, 22:29

the likeliest cause is no vacuum in the servo , press really hard on the pedal & happy days , away you go . Without any vacuum the pedal feels like it has been set in cement , once the engine fires vacuum is generated .

As a last resort reach up the brake pedal & remove switch , you should be able to start engine . Switch is push in clip out

BorderVolvo · Jul 14th, 2020, 07:40

Some systems get the (pedal depressed) signal from a pressure switch in the ABS module, not sure if your model of Volvo will use this .

Maybe a trip to the dealer and some electrickery is required?

Cmjs · Jul 14th, 2020, 08:26

Has happened to me several times. First time it happened I was convinced car was broken and called Volvo asssitance. Just needs really hard push to reach sensor. Not experienced on any other make.

antman99 · Jul 14th, 2020, 08:41

Had exactly yah same in my xc60 SPA, it does seem a little odd but the only good thing I can see is if it was to be so bad that it would not start I would 99% be at home as once it starts the vacuum is back and no problems on the next start.

key76 · Jul 14th, 2020, 09:39

Thanks for all the replies.

Sounds like it’s just a quirk of Volvo then. Whether by deisgn or omission.

Will mention it when I next need to visit dealer for something and see what they say, but sounds “normal”.

BorderVolvo · Jul 14th, 2020, 10:35

At MOT time(to test) the servo should be expelled of air by pumping the pedal and then starting with pressure applied so it shouldn't be a "problem" to start the car in this way?

V8XCV · Jul 14th, 2020, 11:19

I'm assuming this is an auto box? Your pedal sensor may be faulty, with the XC90 the pedal was hard but only required to be pressed a very small amount to allow the engine to start, more like just force on pedal rather than actual pedal travel.

Begonia · Jul 14th, 2020, 11:32

Thanks for telling us about being able to unplug the sensor connection. That's useful to know.

I shall have a nosey under the dash at my earliest convenience.

Jul 13th, 2020, 21:23	#1
key76 Member Last Online: Oct 23rd, 2022 16:59 Join Date: Jun 2019 Location: South	Brake Pedal Force to Start Car Not driving my car much these days and noticed that after it’s been sat for a while the brake pedal goes rock hard. That’s fine, my Merc used to do the same. However the sensor for detecting my foot on pedal to allow me to start car must be way down the travel or the pedal because I have to proper force the pedal to get the car to allow me to start it. Is this normal? Feels wrong. The Merc used to make pedal rock hard, but would always start with very little pressure required on pedal. __________________ S90 T5 R-Design (MY20) in Onyx Black with Polestar Optimisation Perforated Charcoal Nappa Leather with Power Passenger Seat with Memory, Harmon Kardon, Winter Pack, Heated Windscreen, Xenium Pack with IntelliSafe Surround

Jul 13th, 2020, 22:29	#3
dingov70 Master Member Last Online: Apr 22nd, 2024 06:42 Join Date: Jan 2015 Location: Blackpool	the likeliest cause is no vacuum in the servo , press really hard on the pedal & happy days , away you go . Without any vacuum the pedal feels like it has been set in cement , once the engine fires vacuum is generated . As a last resort reach up the brake pedal & remove switch , you should be able to start engine . Switch is push in clip out __________________ To stupidity & beyond

Jul 14th, 2020, 07:40	#4
BorderVolvo Member Last Online: Apr 23rd, 2024 18:57 Join Date: Oct 2018 Location: North of Jedburgh	Some systems get the (pedal depressed) signal from a pressure switch in the ABS module, not sure if your model of Volvo will use this . Maybe a trip to the dealer and some electrickery is required? __________________ V70 2.4 Phase 1.....2435cc.....Registered 31/3/2000.....Leather,AC,CC,etc!.....182k

Jul 14th, 2020, 08:26	#5
Cmjs New Member Last Online: Mar 19th, 2021 07:41 Join Date: Nov 2018 Location: Lancashire	Has happened to me several times. First time it happened I was convinced car was broken and called Volvo asssitance. Just needs really hard push to reach sensor. Not experienced on any other make. __________________ 2018 XC90 R D5 Powerplus, Onyx black with black, Xenium, Winter, BLISS, Apple play, Tow bar

Jul 14th, 2020, 08:41	#6
antman99 VOC Member Last Online: Sep 2nd, 2021 09:24 Join Date: Mar 2015 Location: Westbury	Had exactly yah same in my xc60 SPA, it does seem a little odd but the only good thing I can see is if it was to be so bad that it would not start I would 99% be at home as once it starts the vacuum is back and no problems on the next start. __________________ Past - 2016MY XC60 D4 FWD (VEA) SE Lux Nav Current - 2020MY XC60 T4 FWD Edition EV or Plug in Hybrid? Octopus Go, 5p per KwH for 4 hours at night, £50 credit to each of us if you use my referral link - https://share.octopus.energy/rust-stone-267

Jul 13th, 2020, 21:50	#2
gregg Junior Member Last Online: Dec 21st, 2023 13:02 Join Date: Jan 2008 Location: Surrey	I’ve had exactly the same for the last month or so on my V90 T5 2018, although I’ve been using mine every day. Will be interested also if anyone has an answer..

Jul 14th, 2020, 09:39	#7
key76 Member Last Online: Oct 23rd, 2022 16:59 Join Date: Jun 2019 Location: South	Thanks for all the replies. Sounds like it’s just a quirk of Volvo then. Whether by deisgn or omission. Will mention it when I next need to visit dealer for something and see what they say, but sounds “normal”. __________________ S90 T5 R-Design (MY20) in Onyx Black with Polestar Optimisation Perforated Charcoal Nappa Leather with Power Passenger Seat with Memory, Harmon Kardon, Winter Pack, Heated Windscreen, Xenium Pack with IntelliSafe Surround

Jul 14th, 2020, 10:35	#8
BorderVolvo Member Last Online: Apr 23rd, 2024 18:57 Join Date: Oct 2018 Location: North of Jedburgh	At MOT time(to test) the servo should be expelled of air by pumping the pedal and then starting with pressure applied so it shouldn't be a "problem" to start the car in this way? __________________ V70 2.4 Phase 1.....2435cc.....Registered 31/3/2000.....Leather,AC,CC,etc!.....182k

Jul 14th, 2020, 11:19	#9
V8XCV Member Last Online: Yesterday 16:37 Join Date: Jun 2016 Location: Scotland	I'm assuming this is an auto box? Your pedal sensor may be faulty, with the XC90 the pedal was hard but only required to be pressed a very small amount to allow the engine to start, more like just force on pedal rather than actual pedal travel. __________________ Current V70III 2.4D (163) SE Sport 4C (2008) V70 T5 (1996) V70 P2 D5 EUIII (2002) XC90 V8 4.4 (2007)

Jul 14th, 2020, 11:32	#10
Begonia Member Last Online: Nov 29th, 2020 12:20 Join Date: Feb 2017 Location: Northampton	Thanks for telling us about being able to unplug the sensor connection. That's useful to know. I shall have a nosey under the dash at my earliest convenience.

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