C5. one issue fixed, another comes up. EML light and faults

[aerodynamica]

On the 4h journey back to Glasgow from Wakefield yesterday the C5 was great, refurbished steering (for now) and I even took it through a Wakey car wash that seemed to give a better wash than Ive ever seen... was just a Shell garage but somehow it seemed like the works..

Anyway, about half an hour south of Carlisle the cruise control turned itself off and the warning "Engine management system faulty" and the yellow engine light is now on. This morning I hooked the lexia to it and it came up with several faults for the engine:

Anyone have a more comprehensive idea of what we're looking at here? The one that concerns the most is the P1166 Fuel pressure too high..

I guess the other fault of P1671 is the cruise control fault caused by the engine fault

The car ran ok all the way home - another hour and 40 from the occurrence and it started as normal this morning.

[aerodynamica]

Just looking at that again, the fault for air flow meter says it measures the air inlet at -10c, seems wrong.

[aerodynamica]

Looking up P1166 on here suggests possible benign or terrible causes.. This occurred at motorway speed with cruise on at say, 65-70. Just cruising along really but I had dipped the throttle to overtake quite quickly and it was shortly after that. A suggestion to clear P1166 is to go hard on the throttle for 5 seconds?

Would this in any way be related to the Eolys stuff being low/ empty - I have the refill ready to fill this weekend. May not be related at all.

[GiveMeABreak]

P1671 just relates to Cruise control: Reference speed outside the tolerance, with no further detail.

Your rail pressure shows as being 33 bar over reference values:

Fault Code:	P1166
Description of Fault:	High pressure fuel regulation: Measured rail pressure higher than the maximum pressure. Pressure of the fuel high pressure common injection rail measured higher than the maximum pressure of 1800 bars for 6 seconds.
Conditions for Fault to clear:	Driving for 5 min with several full load accelerations for 10 seconds.
Downgrade Modes whilst Fault is active:	Deactivation of the speed limiter Deactivation speed limiter until the next time the ignition is switched on Deactivation of the cruise control Deactivation cruise control until the next time the ignition is switched on Request for Delayed Engine Stop The ECU limits the fuel flow
Symptoms:	Lack of power Engine hesitating, cutting out
Suspect Areas:	Electrical harness Connectors High pressure fuel pump Engine ECU High pressure fuel sensor

Fault Code:	P0102
Description of Fault:	Flowmeter signal: Measured flow less than the minimum flow. The ECU detects a drift of the air flow signal: The period of the signal for air flow measured exceeds the maximum threshold of 65535 µs corresponding to the minimum threshold for air flow. The fault appears at the end of 300 ms
Conditions for Fault to clear:	Ignition on
Downgrade Modes whilst Fault is active:	Deactivation speed limiter until the next time the ignition is switched on Deactivation cruise control until the next time the ignition is switched on Deactivation of the forced regeneration of the particle emission filter The ECU stops the regulation of the EGR valve
Symptoms:	Smoke from the exhaust
Suspect Areas:	Air flow meter Electrical harness Engine ECU

Fault Code:	P0112
Description of Fault:	Intake air temperature signal (Air flow meter): Short circuit to earth; Value too low. The voltage of the inlet air temperature sensor signal is lower than the minimum threshold corresponding to a temperature of -49.9°C for more than 5 seconds.
Conditions for Fault to clear:	Ignition on
Downgrade Modes whilst Fault is active:	Deactivation of the coherence faults of the flowmeter
Symptoms:	Jerking/stalling Lack of power
Suspect Areas:	Air temperature sensor on the flowmeter Electrical harness Engine ECU

[aerodynamica]

Thanks Marc, I was hoping the air flow meter fault was simply caused by my accidental running of the engine with the air filter (and the sensor) removed while changing the transmission fluid last weekend.

The first fault P1166, hasn't so far shown any symptoms such as low power. Just wonder if the 'Driving for 5 min with several full load accelerations for 10 seconds.' suggestion is a good idea.

[GiveMeABreak]

There's definitely something it's not happy about that possibly will have a knock-on effect on other systems, so I'd always start with the specifics like the Air flow Meter as if that's faulty it will result in incorrect fuelling which may be your other issue.

[aerodynamica]

Thanks Marc

[RichardW]

They're all showing max, my guess would be something has temporarily shorted the 5v reference. As to what....???

[aerodynamica]

Hm not sure Richard. I just tried the full throttle several times over 5 minutes. Stopped at a service station to top up the washer fluid, bought an expensive coffee, probably waited 8- 10 minutes, hit the road again and voila! The engine light went away.... i have ordered a new air flow sensor anyway.

Incidentally, I've just topped up the fuel additive and managed to reset the counter via the old Lexia.

Will see how it goes...