Fuel pump relay.
#2
01-31-2018, 05:23 PM
For a 2008 LR2 the power for the fuel pump flows as follows
High current connection
1. Battery +
2. F17 - Fuse box in engine bay
3. F22 - Fuse box in passenger compartment
4. Relay soldered to PCB in passenger compartment (PCB is above F22)
5. Fuel pump module (converts DC to 3 phase AC to power the pump)
6. Fuel pump motor
7. Ground for fuel pump connected to chassis
8. Battery -
For my 2008 it would stall at the gas station if I left the key docked due to heat soaking. To fix the problem I stopped leaving the key docked.
But first I bough a current meter that could measure the current to the fuel pump module.
This is what I bought.
To check that the fuel pump is running just remove F22 by the front passengers feet and measure the current
Note: when I heat soak my LR2 with the key docked the ECU thinks that I have plenty of pressure to start (and it doesn't turn on the pump) but I am reasonably certain that the fuel is vapor and not liquid so the amount injected is too little and my LR2 won't start
What problem are you trying to solve?
If F17 or F22 are broken you won't get any power to the fuel pump.
F17 can be seen in this thread
Freel2.com - View topic - Accessing fuses 16-21 in Engine compartment fuse box
Good Luck
Paul
High current connection
1. Battery +
2. F17 - Fuse box in engine bay
3. F22 - Fuse box in passenger compartment
4. Relay soldered to PCB in passenger compartment (PCB is above F22)
5. Fuel pump module (converts DC to 3 phase AC to power the pump)
6. Fuel pump motor
7. Ground for fuel pump connected to chassis
8. Battery -
For my 2008 it would stall at the gas station if I left the key docked due to heat soaking. To fix the problem I stopped leaving the key docked.
But first I bough a current meter that could measure the current to the fuel pump module.
This is what I bought.
To check that the fuel pump is running just remove F22 by the front passengers feet and measure the current
Note: when I heat soak my LR2 with the key docked the ECU thinks that I have plenty of pressure to start (and it doesn't turn on the pump) but I am reasonably certain that the fuel is vapor and not liquid so the amount injected is too little and my LR2 won't start
What problem are you trying to solve?
If F17 or F22 are broken you won't get any power to the fuel pump.
F17 can be seen in this thread
Freel2.com - View topic - Accessing fuses 16-21 in Engine compartment fuse box
Good Luck
Paul
#3
01-31-2018, 05:47 PM
Thanks for all the details.
My problem is the car will occasionally stall on ignition, ~30 ignitions. It starts then shudders to a stall. After 3-4 attempts if starts up.
It is not related to temperature, does it on warm and cold days. I use premium gas, have tried octane boosters and fuel cleaners and the battery is strong.
Dealer thinks it is the fuel pump, but I’m reluctant to put another $1200 into this car. Changed rear diff and starter motor last year.
A friend suggested changing the fuel sensor relay but I couldn’t find it.
Also tried disconnecting battery to reset the computer.
It still does it.
Many thoughts, suggestions?
Thanks.
Andrew.
My problem is the car will occasionally stall on ignition, ~30 ignitions. It starts then shudders to a stall. After 3-4 attempts if starts up.
It is not related to temperature, does it on warm and cold days. I use premium gas, have tried octane boosters and fuel cleaners and the battery is strong.
Dealer thinks it is the fuel pump, but I’m reluctant to put another $1200 into this car. Changed rear diff and starter motor last year.
A friend suggested changing the fuel sensor relay but I couldn’t find it.
Also tried disconnecting battery to reset the computer.
It still does it.
Many thoughts, suggestions?
Thanks.
Andrew.
#4
01-31-2018, 06:24 PM
Andrew,
Does your LR2 have auto start stop?
Does your LR2 dock its key or have key-less ignition?
When do you get the problem with failure to start? I need details.
For my LR2 If I go to the gas station fill up the tank and and I leave my key docked then my LR2 wont start.
The ECU runs the fuel pump for a few seconds to build pressure and once the pressure is achieved it expects the engine to start.
Its a safety thing, the fuel pump doesn't want to run unless the engine is running in case your fuel line is broken no point in spilling fuel all over the ground.
Here is the detail that I need to know
Cold start in the morning - sometimes fails to start or always starts
Short trip then hot restart (car locked) - sometimes fails to start or always starts
Long trip hot restart (car locked) - sometimes fails to start or always starts
Short trip then hot restart (car not locked) - sometimes fails to start or always starts
Long trip hot restart (car not locked) - sometimes fails to start or always starts
Good Luck
Paul
Does your LR2 have auto start stop?
Does your LR2 dock its key or have key-less ignition?
When do you get the problem with failure to start? I need details.
For my LR2 If I go to the gas station fill up the tank and and I leave my key docked then my LR2 wont start.
The ECU runs the fuel pump for a few seconds to build pressure and once the pressure is achieved it expects the engine to start.
Its a safety thing, the fuel pump doesn't want to run unless the engine is running in case your fuel line is broken no point in spilling fuel all over the ground.
Here is the detail that I need to know
Cold start in the morning - sometimes fails to start or always starts
Short trip then hot restart (car locked) - sometimes fails to start or always starts
Long trip hot restart (car locked) - sometimes fails to start or always starts
Short trip then hot restart (car not locked) - sometimes fails to start or always starts
Long trip hot restart (car not locked) - sometimes fails to start or always starts
Good Luck
Paul
#5
01-31-2018, 07:09 PM
My problem is not a failure of the car to start, it is failure to stay running after ignition.
The last time it happened I drove 5 miles to hardware store on 60’ day, came out 20 min later, ignition, tachometer to 700, shudder down to 400 then stall. After 3-4 attempts with same symptoms, car started and ran fine.
Time before that, cold day 30 + mile journey at 70 mph, pulled over to get gas, did same thing on restart, ignition shudder stall. 3 ignition attempts and all good.
That is pretty much what happens whenever it decides to do it, maybe 10 times total, again, unrelated to outside temperatures or how long the previous journey was or time of day.
Also did OBD computer diagnostic. No codes.
Not sure what auto start/stop is.
Key stays docked when driving.
Thanks
The last time it happened I drove 5 miles to hardware store on 60’ day, came out 20 min later, ignition, tachometer to 700, shudder down to 400 then stall. After 3-4 attempts with same symptoms, car started and ran fine.
Time before that, cold day 30 + mile journey at 70 mph, pulled over to get gas, did same thing on restart, ignition shudder stall. 3 ignition attempts and all good.
That is pretty much what happens whenever it decides to do it, maybe 10 times total, again, unrelated to outside temperatures or how long the previous journey was or time of day.
Also did OBD computer diagnostic. No codes.
Not sure what auto start/stop is.
Key stays docked when driving.
Thanks
#6
01-31-2018, 09:21 PM
Andrew,
Your LR2 has the same setup as mine
Here is my recommendation of what I would do if I were in your position
* open door and enter vehicle
* dock the key
* count to three
* step on the brake and hold it down
* count to three
* press the start button
* select gear and release the brake
The pauses between steps are important the various computers are doing thing and they need time
If the engine starts and runs rough then shut it down and remove the key and do the steps in order shown above
Let me know if you want more details about what is happening and I will direct you to some links
Good luck
Paul
Your LR2 has the same setup as mine
Here is my recommendation of what I would do if I were in your position
* open door and enter vehicle
* dock the key
* count to three
* step on the brake and hold it down
* count to three
* press the start button
* select gear and release the brake
The pauses between steps are important the various computers are doing thing and they need time
If the engine starts and runs rough then shut it down and remove the key and do the steps in order shown above
Let me know if you want more details about what is happening and I will direct you to some links
Good luck
Paul
#7
02-01-2018, 09:37 AM
Thanks again for the information. I will do as you suggest.
What are the links you mentioned? I have searched the web and read stories of similar problems with LR2’s, but I haven’t found anything telling of the actual diagnosis or the solution.
This only started happening 2 months ago, I would like for it to never happen again.
Andrew.
What are the links you mentioned? I have searched the web and read stories of similar problems with LR2’s, but I haven’t found anything telling of the actual diagnosis or the solution.
This only started happening 2 months ago, I would like for it to never happen again.
Andrew.
#8
02-01-2018, 09:53 AM
Andrew,
Its been my experience that an old battery and/or and old starter motor can cause electrical problems.
I see you replaced your starter motor
how old is your battery? I replaced my first battery at 4 years and my second battery at 9 years.
Does this describe your problem
UNDER CERTAIN CONDITIONS THE SOFTWARE WITHIN THE CENTRAL ELECTRONIC MODULE (CEM) MAY NOT SEND A SIGNAL TO THE FUEL PUMP ELECTRONIC MODULE (PEM). THIS MISSING SIGNAL TO THE PEM INHIBITS THE START OF THE FUEL PUMP. THE DRIVER MAY BE ABLE TO START THE ENGINE IN SPITE OF THE FUEL PUMP NOT BEING ACTIVATED DUE TO RESIDUAL PRESSURE IN THE FUEL SYSTEM. IN SOME CASES, THE DRIVER MAY BE ABLE TO DRIVE THE VEHICLE A SHORT DISTANCE AT IDLE BUT THEN THE ENGINE MAY STALL.
The engine in our LR2 is made by Volvo and it is used in several Volvo models (XC70, XC90, S80, S60, etc) The information above is from a Volvo recall, supposedly Volvo and Land Rover fixed this problem with software.
For me I just follow the steps shown above and the problem doesn't happen any more.
Remember to remove the key with the engine stalled
* foot off the brake
* press start stop button
* undock key
* repeat steps shown above (pausing between steps)
Some links
https://landroverforums.com/forum/lr...se-help-78491/
https://www-odi.nhtsa.dot.gov/owners...rod_ids=288628
Good Luck
Paul
PS my LR2 never fails to start if I remember to pause.
Its been my experience that an old battery and/or and old starter motor can cause electrical problems.
I see you replaced your starter motor
how old is your battery? I replaced my first battery at 4 years and my second battery at 9 years.
Does this describe your problem
UNDER CERTAIN CONDITIONS THE SOFTWARE WITHIN THE CENTRAL ELECTRONIC MODULE (CEM) MAY NOT SEND A SIGNAL TO THE FUEL PUMP ELECTRONIC MODULE (PEM). THIS MISSING SIGNAL TO THE PEM INHIBITS THE START OF THE FUEL PUMP. THE DRIVER MAY BE ABLE TO START THE ENGINE IN SPITE OF THE FUEL PUMP NOT BEING ACTIVATED DUE TO RESIDUAL PRESSURE IN THE FUEL SYSTEM. IN SOME CASES, THE DRIVER MAY BE ABLE TO DRIVE THE VEHICLE A SHORT DISTANCE AT IDLE BUT THEN THE ENGINE MAY STALL.
The engine in our LR2 is made by Volvo and it is used in several Volvo models (XC70, XC90, S80, S60, etc) The information above is from a Volvo recall, supposedly Volvo and Land Rover fixed this problem with software.
For me I just follow the steps shown above and the problem doesn't happen any more.
Remember to remove the key with the engine stalled
* foot off the brake
* press start stop button
* undock key
* repeat steps shown above (pausing between steps)
Some links
https://landroverforums.com/forum/lr...se-help-78491/
https://www-odi.nhtsa.dot.gov/owners...rod_ids=288628
Good Luck
Paul
PS my LR2 never fails to start if I remember to pause.
#9
02-01-2018, 10:43 AM
Thanks.
That does describe the problem. When it does happen again I’ll undock the key and be patient.
Its reassuring to know it’s not the fuel pump, but I’m way out of warranty, so a software update would be at my expense. I’ll just have to accept it as a Land Rover quirk.
Thank you you again for all your info and insight. The dealership wanted me to leave it with them for a couple days so they could replicate the problem.. Also said they had never heard of any LR 2 with these issues I described.
Andrew.
That does describe the problem. When it does happen again I’ll undock the key and be patient.
Its reassuring to know it’s not the fuel pump, but I’m way out of warranty, so a software update would be at my expense. I’ll just have to accept it as a Land Rover quirk.
Thank you you again for all your info and insight. The dealership wanted me to leave it with them for a couple days so they could replicate the problem.. Also said they had never heard of any LR 2 with these issues I described.
Andrew.
#10
02-05-2018, 10:20 AM
