U1218 code after diagnostic check

[Psmk222]

I have a couple of issues with my c4 grand picasso... first of all I got the dpf additive level low message . I refilled the tank but the message remained with the p15b3 fault code. I then took it in to the garage where a guy looked at it with his diagnostic machine but couldn't reset the counter but the tank was showing as 99% full. I then got an other fault code for the additive pump....p1435... then literally as I was driving away from the garage I get another check engine warning and I now have a u1218 fault.

Another guy in the garage reckons I should just replace the additive tank with the new one I've just bought and that should clear the fault codes but from what I've read elsewhere that isn't quite the case and even if I replace the tank I'll still have the faults.

Is it possible for me to change the tank myself then take it to a main dealer to have the codes reset or would they want to fit thier own tank..

Also is the u1218 code due to the garage messing with the additive functions with the machine.

P1435
P15b3
U1218

[GiveMeABreak]

Pop your VIN up so I can relate the faults to the correct EMS.

[Psmk222]

VF7**************[VIN obfuscated, can be read by forum staff]

Thanks

U1218 reads as: BSI clearing of the high frequency control reawakening fault

[GiveMeABreak]

First of all you really need to get it to somebody who knows what they're doing regarding resetting the additive counter. Not only does it have to be reset, but may also need priming if the fluid has been allowed to run low.

If the system has not been reset then you will get faults like this. They may have attempted it, but left the multiplexed pump in limbo if it has been attempted but not completed, and the likelihood of comms errors with the multiplexed additive pump.

The other thing is make sure you are not running the vehicle on low fuel! The additive pump depends on sufficient fuel to meter out the additive doses, but constantly adding small amounts of fuel can complicate the issue as you can see - with at least 10 litres of fuel needing to be added.

Fault Code:	P1435
Description of Fault:	Multiplexed additive pump: CAN network fault or pump fault. Description of the diagnostics: Possibility 1 Multiplexed additive pump fault detected for 10 second Possibility 2 Fault in communication between the built-in systems interface and the additive pump detected for 10 second.
Conditions for Fault to clear:	The following conditions have to be met - Addition of 10 litres of fuel - Driving with the engine hot for 5 minutes
Downgrade Modes whilst Fault is active:	Transmission to the multifunction screen of "risk of clogging of the particle filter" Deactivation of the request for regeneration of the particle filter from the diagnostic tool Switching to fuel "normal reduced flow" mode Switching on of the warning lamp and/or warning message: "SERVICE" warning lamp
Symptoms:	Fluid leak/smells (diesel fuel, oil, etc.) No effects immediately perceptible to the customer
Suspect Areas:	Soft pouch/Particle filter additive reservoir Additive pump TI Additive pump MGI

The P15B3 fault below, concerns the same issue I referred to above - the additive system has not been reset properly and therefore the engine ECU is still telling you it is too low!
There is no physical measurement (no gauge) for determining additive level - it is calculated and this is why it is essential to reset it. I suggest if you can't find a competent person with the right equipment to do this, then you may have to pay a dealer diagnostic time to do it for you.

Fault Code:	P15B3
Description of Fault:	Additive adding: Additive level calculated lower than the minimum threshold. Description of the diagnostics: The engine management ECU indicates that the additive minimum level has been reached.
Conditions for Fault to clear:	Driving for 5 minutes
Downgrade Modes whilst Fault is active:	Display of the message "Risk of clogging of the particle filter" Deactivation of the request for regeneration of the particle filter from the diagnostic tool Switching to fuel "normal reduced flow" mode Switching on of the warning lamp and/or warning message: "SERVICE" warning lamp
Symptoms:	-
Suspect Areas:	Particle filter additive reservoir Particle filter additive

In this context, U1218 is telling you there's a fault in the data stream, so again this may be because the garage has failed to reset it correctly and left it in a conflicting state.

Fault Code:	U1218
Description of Fault:	Intersystems CAN: One of the parameters present in a datastream sent by the BSI is invalid. Description of the diagnostics: Faults in communication between ECUs on the CAN network Conditions of activation of the diagnostics: At least one of the following conditions must be fulfilled: - Ignition switched on - Engine running
Conditions for Fault to clear:	Driving for 5 minutes
Downgrade Modes whilst Fault is active:	Switching on of the warning lamp and/or warning message: "SERVICE" warning lamp.
Symptoms:	Jerking/stalling Starting problem Lack of power
Suspect Areas:	Engine ECU Intersystem CAN network

[Psmk222]

Hi .. thanks for the reply...I think the guy that was doing thy diagnostics didn't really have a clue what he was doing and was pretty much just playing around with it and never charged me as he couldn't fix the issue...I have just bought a complete new tank with the pump included as I couldn't buy the pump on its own as they told me the pump was faulty. I was going to fit it then ask the main dealer to do the reset which they have agreed to do on the 1st of October... do you think I should replace the additive tank with the new one or is it more likely that the pump is actually OK and will start working when reset by the more competent main dealer.

[GiveMeABreak]

That's something I can't answer on a Forum, as it would need further checks on the pump module. Consider that if you have already bought a new pump / tank assembly and it is the correct one for your vehicle, then it may be cheaper for you if the dealership just resets it - rather than fitting the old one, charging you time - and it doesn't work, where you'll then have to fit the new one and repeat.

This assumes that a) the fault was in the tank assembly / pump module and not a reset fault, and b) that there isn't a wiring fault from the pump assembly to the engine ECU. This has been known to happen where the wiring has worn from the pump back.

So difficult to diagnose from here as you can appreciate. If there is a wiring fault from the engine ECU to the pump, then of course this would of prevented it resetting - and again caused these relevant faults.

[Psmk222]

Agreed.. thank you very much for your help