Faults and errors, need advice

[Wynand007]

Hi, I have posted about some error codes on my C2. Its a 2006 VTR 1.4 8 valve. The error code is Daul altenator lamp P1108 map
To baro compareson to high. This doesnt happen while driving in town, but
driving on the freeway for about 20 to 30 minutes the code pops up
Then i stop and reset to code with my scanner, and its fine for another few minutes. There is
no lack in preformance, but it runs rich, as you can see with the fuel consumption, every
time the code apear. Map sensor and O2 sensors was replace, all earth points and connectons
were check. Doing a live data read, i picked up that there is a reading
that says fuel system 1 OL fault with the engine temp at 85 celsius.

Do you have any advice

[GiveMeABreak]

Hi

P1108 relates to the adaptation of air entering the inlet manifold fault. I would also suggest looking at the motorised throttle housing itself.

Here's some info to help you troubleshoot.

The role of the Motorise Throttle Housing:

• Dose the quantity of air admitted in the cylinders.
• The request to open the air regulating flap is no longer a direct command by cable linked to the accelerator pedal.
• An accelerator pedal sensor informs the injection ECU of the driver’s request.
• The injection ECU then controls the motorised throttle housing motor.
• A potentiometer incorporated in the motorised throttle housing enables the injection ECU to determine the exact position of the air butterfly.

A Throttle position at rest (ignition off) or "limp home" position in the event of failure.
B Position of the gas butterfly with the ignition on or at idle.
C Position of the butterfly at full load.
"a" Force of the butterfly motor.
"b" Force of the spring.
With the ignition off, the "limp home" spring holds the butterfly open (See A).
When the ignition is switched on, the injection ECU controls the throttle to the idle position countering the force of the return spring (In the case of a down-grade operating mode, placing in the "limp home" position) (See B).
When the engine is at idle, the motorised throttle housing throttle moves to supply the flow of air required by the engine (Replaces the idle regulation stepper motor).
From 1500 rpm, the injection ECU controls the throttle in the other direction to assist the return spring (In the case of a down-grade operating mode, placing in the "limp home" position) (See C).
The position of the throttle is monitored by the injection ECU (Potentiometer incorporated in the motorised throttle housing).
The injection ECU cuts off the supply to the throttle housing if certain faults are present.

Electrical special features

Control: injection ECU.
Variable voltage control (OCR):

• Opening of the throttle: Positive OCR voltage
• Closing of the throttle: Negative OCR voltage

N.B.: OCR: opening cyclic ratio.

The throttle housing is closed by a return spring (In the case of a down-grade operating mode, placing in the "limp home" position).
If the throttle becomes clogged, the injection ECU supplies the motorised throttle housing motor with a negative voltage (Displaying of the parameter measurements on the diagnostic equipment).

Allocation of channels of connector:
Terminal 1 : Supply 5 V
Terminal 2 : Throttle position signal 1
Terminal 3 : (+) engine
Terminal 4 : (-) engine
Terminal 5 : Earth (Potentiometer )
Terminal 6 : Throttle position signal 2

Throttle open - Fully open:

• Voltage between earth and track 2: 4,45 to 4,95 Volts
• Voltage between earth and track 6: 0,05 to 0,55 Volts

Throttle closed - Closed position:

• Voltage between earth and track 2: 0,3 to 0,7 Volts
• Voltage between earth and track 6: 4,3 to 4,7 Volts

Position of the throttle in down-grade mode:

• Voltage between earth and track 2: 0,66 to 1,23 Volts
• Voltage between earth and track 6: 3,7 to 4,4 Volts