Hi everyone!
I have a 2014 1.6L Citroen C4 Grand Picasso that had problems starting.
RAC said it was a weak fuel pump. took it to a Garage said who had to call an electrician out. He said:
“Diagnostics found intermittent fault with SCR system. Fuel additive module has fault with communication to engine ecu.
“Wiring checks done but because of the intermittent fault there was no fault found at the time of tests.
“Its possible for the main SCR tank and module to be at fault but until this fails permanently no diagnoses can be 100 percent.”
The Garage has said to go to the main dealer, who will charge me £312 for diagnostics.
Can anyone help with this please?
Problem with Fuel additive and engine ECU
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Re: Problem with Fuel additive and engine ECU
That's confusing 2 separate technologies and won't be the first time I've heard this.....
The Diesel Particulate Filter (DPF) system is completely separate to the SCR (Selective Catalytic Reduction) system.
1) The DPF uses an additive injected from the Eolys reservoir into the fuel tank each time fuel is added. This is to help reduce the exhaust gas temperature needed to burn of the trapped particles in the DPF during regeneration.
2) Separate to that the SCR system treats the NOx emissions by injecting Urea (Adblue) into the catalytic converter. The Adblue is contained in a separate tank.
You may well have a DPF additive pump fault for the Eolys additive, but he seems to be mixing that up in the same sentence as the SCR.
You may also have a fault with the Adblue Tank which contains the Urea pump, or the Urea injector or harness.
So these are separate issues and you need to take it to either a dealer or a proper garage that knows what they are on about to get a proper diagnostic done. Any faults with these systems will generally have fault codes stored that can be retrieved. If you have the actual codes, pop them up here with your VIN and we may be able to help.
Without a proper diagnostic you will be wasting money with garages that don't know what they are doing.
Further, £312 for dealer diagnostics is also BS.
Citroen have a standard hourly rate for diagnostics and it won't take them that long to return the faults. So I don't know where they are getting that from!
£120, see for yourself:
https://www.citroen.co.uk/maintain/fixe ... &gclsrc=ds
The Diesel Particulate Filter (DPF) system is completely separate to the SCR (Selective Catalytic Reduction) system.
1) The DPF uses an additive injected from the Eolys reservoir into the fuel tank each time fuel is added. This is to help reduce the exhaust gas temperature needed to burn of the trapped particles in the DPF during regeneration.
2) Separate to that the SCR system treats the NOx emissions by injecting Urea (Adblue) into the catalytic converter. The Adblue is contained in a separate tank.
Adblue is not added to the fuel - so they are talking nonsense here.Diagnostics found intermittent fault with SCR system. Fuel additive module has fault with communication to engine ecu.
You may well have a DPF additive pump fault for the Eolys additive, but he seems to be mixing that up in the same sentence as the SCR.
You may also have a fault with the Adblue Tank which contains the Urea pump, or the Urea injector or harness.
So these are separate issues and you need to take it to either a dealer or a proper garage that knows what they are on about to get a proper diagnostic done. Any faults with these systems will generally have fault codes stored that can be retrieved. If you have the actual codes, pop them up here with your VIN and we may be able to help.
Without a proper diagnostic you will be wasting money with garages that don't know what they are doing.
Further, £312 for dealer diagnostics is also BS.
Citroen have a standard hourly rate for diagnostics and it won't take them that long to return the faults. So I don't know where they are getting that from!
£120, see for yourself:
https://www.citroen.co.uk/maintain/fixe ... &gclsrc=ds
Please Don't PM Me For Technical Help
Marc
Marc
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Re: Problem with Fuel additive and engine ECU
Marc,
Thank you so much for the informative and helpful reply.
I am pursuing the Garage and their electrician for the error codes and will post when I have them.
When RAC got the car started, they did give me an error report with these codes:
DTC: P2291,The rise in pressure in the injection rail is too slow on starting
DTC: P050B,Starting time too long
System Type: ENGINE SYSTEM TEST/VALUES
Name: 9HR - SID 807
DTC: P2291,Rail pressure inadequate at starting
DTC: P050B,Starting time too long
I only seem to have this problem when the car is pointing up hill on my driveway (it’s on a slight incline) and never when facing down hill. It’s also never happened anywhere else…
Hope these codes help and if I find any more I’ll let you know.
Thank you so much again.
Thank you so much for the informative and helpful reply.
I am pursuing the Garage and their electrician for the error codes and will post when I have them.
When RAC got the car started, they did give me an error report with these codes:
DTC: P2291,The rise in pressure in the injection rail is too slow on starting
DTC: P050B,Starting time too long
System Type: ENGINE SYSTEM TEST/VALUES
Name: 9HR - SID 807
DTC: P2291,Rail pressure inadequate at starting
DTC: P050B,Starting time too long
I only seem to have this problem when the car is pointing up hill on my driveway (it’s on a slight incline) and never when facing down hill. It’s also never happened anywhere else…
Hope these codes help and if I find any more I’ll let you know.
Thank you so much again.
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Re: Problem with Fuel additive and engine ECU
The main issue is Fault P2291 which is: Starting monitoring: Pressure increase in the injection rail too slow when starting. Fuel injection common rail pressure increase time too long (Threshold at 700 ms when the coolant temperature is 5°C).
The main culprit may be a lack of fuel getting to the high pressure pump and then the rail.
These are the main suspects, but when did you last have the diesel fuel filter changed? If that gets any crap in it from the fuel tank (especially if you regularly run the vehicle with low fuel levels in the tank) this can lead to diesel bugs / sludge or other contamination in the filter and this can cause a fuel supply problem.
Suspects
The main culprit may be a lack of fuel getting to the high pressure pump and then the rail.
These are the main suspects, but when did you last have the diesel fuel filter changed? If that gets any crap in it from the fuel tank (especially if you regularly run the vehicle with low fuel levels in the tank) this can lead to diesel bugs / sludge or other contamination in the filter and this can cause a fuel supply problem.
Suspects
- Air leak on the fuel filter
- Clogging of the fuel filter
- Running out of fuel
- Leak in fuel circuit (low pressure)
- Fuel high pressure flow regulator
- High pressure fuel pump
- Leak on the high pressure fuel pipes
- Leak on the fuel high pressure common injection rail
- Fuel injectors
- Electrical harnesses
- Connectors
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Re: Problem with Fuel additive and engine ECU
It could also be a weak battery or starter causing the engine and hp pump to be cranking too slowly to raise sufficient pressure, the cranking speed should also be checked as part of the diagnostic.
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Re: Problem with Fuel additive and engine ECU
Thank you both, really helpful.
I’ve been told that there wasn’t an issue with the battery or the fuel filter, so I’m trying to get hold of the electrician to see if he can elaborate any more on his report.
I’m really grateful for all the support shown here!
I’ve been told that there wasn’t an issue with the battery or the fuel filter, so I’m trying to get hold of the electrician to see if he can elaborate any more on his report.
I’m really grateful for all the support shown here!
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Re: Problem with Fuel additive and engine ECU
No problem, but I'm not sure how anyone can say you haven't an issue with the fuel filter to be honest - it's not like it will be a different colour...
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Marc
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Re: Problem with Fuel additive and engine ECU
The garage finally came back with the following from the electrician:
“Fault code U029D-87 fault code comms with adblue De nox system. Only work for the trade
“Also because it’s intermittent warranty company may not entertain it till it faults constantly”
“Fault code U029D-87 fault code comms with adblue De nox system. Only work for the trade
“Also because it’s intermittent warranty company may not entertain it till it faults constantly”
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Re: Problem with Fuel additive and engine ECU
Ok, so that's a completely new code which is a fault with the downstream NOx sensor or communication with it. If the Downstream NOx sensor or is either faulty or not sending data, which in this case the fault indicates the engine ECU is not getting any data, then it means it can't monitor the NOx levels of the exhaust gasses. So it needs further investigation to find out the issue, but here are the pointers. It may of course also mean that the electrical connection to the sensor is faulty which would also cause the lack of data or operation of the sensor.
Fault Code: | U029D 87 |
Description of Fault: | Emissions control CAN network (Downstream NOx sensor) : Missing information. Fault in communication with the NOx sensor : Information absent. |
Conditions for Fault to clear: | At least one of the following conditions must be fulfilled - After switching the ignition off and then back on - Driving for 5 minutes |
Downgrade Modes whilst Fault is active: |
|
Symptoms: | None Reported |
Suspect Areas: |
|
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Marc
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Re: Problem with Fuel additive and engine ECU
I think i may have the same issue. Hoping someone is still monitoring this thread because i'm struggling to find anyone who can help.
The engine light of my 2014 C4 Grand Picasso (70k miles and just purchased) came on earlier this week. Took it to Halfords for a diagnostic and they reported back a long list of errors but the main issue they flagged up was B1811 Fault on diesel fuel additive pump.
Halfords said it was something that only Citroen garage could resolve but they can't see me until later this month. Called a local Citroen specialist and they also have no availability to look at the car. When I called, neither of them seemed to know what this error meant!
As far as I know, the car doesn't use adblue although I'm new to this technology so not sure what i'm looking for.
Does anyone have any advice? I'm due to drive the car to London this weekend so not sure if it's wise to risk it.
The engine light of my 2014 C4 Grand Picasso (70k miles and just purchased) came on earlier this week. Took it to Halfords for a diagnostic and they reported back a long list of errors but the main issue they flagged up was B1811 Fault on diesel fuel additive pump.
Halfords said it was something that only Citroen garage could resolve but they can't see me until later this month. Called a local Citroen specialist and they also have no availability to look at the car. When I called, neither of them seemed to know what this error meant!
As far as I know, the car doesn't use adblue although I'm new to this technology so not sure what i'm looking for.
Does anyone have any advice? I'm due to drive the car to London this weekend so not sure if it's wise to risk it.
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Re: Problem with Fuel additive and engine ECU
First thing to do is provide me with your VIN (please post your VIN in full without spaces - it will be automatically masked from public view after submitting your post & will only be visible to staff), so I can see exactly what you have and see if this is a valid fault code.
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Marc
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