any ideas on this code? >>
04-27-2006, 04:29 AM
#1
AudiWorld Super User
Thread Starter
any ideas on this code? >>
17579 - Angle Sensor 2 for Throttle Actuator (G188) Implausible Signal
P1171 - 35-10 - - - Intermittent
...this little guy keeps throwing me into limp mode with EPC and CEL. happens under very little acceleration. I bought a new ("used") throttle body to see if the code would go away - it did not. I am out of ideas.
Andrew
P1171 - 35-10 - - - Intermittent
...this little guy keeps throwing me into limp mode with EPC and CEL. happens under very little acceleration. I bought a new ("used") throttle body to see if the code would go away - it did not. I am out of ideas.
Andrew
04-27-2006, 05:16 AM
#5
Bentley says...(edited)>
Throttle body, but since the pedal potentiometer is integrated into the whole system, maybe that's it..Check and clean the plug connections at both ends to start.
Both codes are the same thing per Bentley..
Both codes are the same thing per Bentley..
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04-27-2006, 09:30 AM
#9
It's pretty involved...
And this is just part of it..
Operation of electronic throttle system
With the electronic throttle the throttle valve is not operated by a cable connected to the accelerator pedal . There is no mechanical link between the accelerator and the throttle valve.
The position of the accelerator pedal is communicated to the engine control module by two accelerator position senders (variable resistors, both fitted in a single housing) which are connected to the accelerator pedal .
The accelerator position (as determined by the driver) is one of the main input values for the engine control module.
The throttle valve is actuated by a servomotor (throttle valve positioner) in the throttle valve control module over the full range of engine speeds and load conditions.
The throttle valve positioner actuates the throttle valve according to the commands it receives from the engine control module.
When the ignition is on and the engine is not running, the engine control module operates the throttle valve positioner in exact accordance with the signals from the accelerator position senders. For example, when the accelerator is pressed down half way, the throttle valve positioner opens the throttle valve by an equivalent amount, i.e. about half way.
--------------------------------------------------------------------------------
24-136
When the engine is running (i.e. under load) the engine control module can open and close the throttle valve freely (i.e. independently of the signals being sent by the accelerator position sender).
For example, the throttle valve might already be fully open even though the accelerator is only pressed down half way. This has the advantage of preventing throttling losses at the throttle valve.
Under certain engine load conditions there is also a significant reduction in harmful emissions and noticeably improved fuel consumption.
The engine control module can provide the optimum combination of throttle valve opening and charge pressure in order to create the required torque.
The electronic throttle is not simply a combination of two or three components, but rather a complete system comprising all the elements that together determine the position of the throttle valve and also control and monitor it. For example, the accelerator position sender, throttle valve control module, EPC warning lamp, engine control module etc.
--------------------------------------------------------------------------------
24-137
Electronic throttle warning lamp in instrument cluster
Note:
Electronic throttle warning lamp -K132 is also known as the EPC warning lamp (EPC = electronic power control).
"EPC" stands for Electronic Power Control and refers to the electronic throttle control system.
Fitting location of EPC warning lamp
When the ignition is switched on the engine control module tests all the components whose functions relate to the electronic throttle system.
The engine control module activates the EPC warning lamp when the ignition is switched on. The warning lamp will go out soon after the engine starts, provided that the engine control module does not detect any faults in the electronic throttle system and the activation of the lamp via the engine control module is working properly.
If a fault is detected in the electronic throttle system while the engine is running, the engine control module will activate the EPC warning lamp (see Fault Table for list of possible faults). At the same time a Diagnostic Trouble Code (DTC) is stored in the Diagnostic Trouble Code (DTC) memory of the engine control module.
Display Group 062: Electronic throttle potentiometer voltages
Display
xx %
xx %
xx %
xx %
Indicates
Throttle valve angle
(angle sender 1)
Throttle valve angle
(angle sender 2)
Accelerator position
sender 1
Accelerator position
sender 2
Specification
3 to 93 %
97 to 3 %
12 to 97 %
4 to 49 %
Note:
The engine control module converts the voltage readings from the angle senders into percentages of 5 V and displays them as percentages. (A supply voltage of 5 V is equivalent to 100%.)
- Observe display zones 1 and 2.
- Slowly depress accelerator to full throttle position.
The percentage value in display zone 1 should rise steadily between 3 and 93 % but without covering the full range of values.
The percentage value in display zone 2 should fall steadily between 97 and 3 % but without covering the full range of values.
--------------------------------------------------------------------------------
24-150
Notes:
The reason why the value in display zone 1 rises and the value in display zone 2 falls is because the potentiometers (angle senders) in the throttle valve control module work in opposite directions.
The percentage value for the first potentiometer increases as the voltage rises toward 5 V because the voltage at this potentiometer increases as the throttle valve opens.
The percentage value for the second potentiometer decreases as the voltage drops away from 5 V and toward 0 V because the voltage at this potentiometer decreases as the throttle valve opens.
- Press the button to exit from the function "08 - Read data block".
If the display values do not appear as described:
- Test voltage supply and wiring to throttle valve control module Page 24-151 . Pay particular attention to the connectors, which may have corroded or become detached.
- Test accelerator position senders Page 24-153 .
It's pretty involved!
Operation of electronic throttle system
With the electronic throttle the throttle valve is not operated by a cable connected to the accelerator pedal . There is no mechanical link between the accelerator and the throttle valve.
The position of the accelerator pedal is communicated to the engine control module by two accelerator position senders (variable resistors, both fitted in a single housing) which are connected to the accelerator pedal .
The accelerator position (as determined by the driver) is one of the main input values for the engine control module.
The throttle valve is actuated by a servomotor (throttle valve positioner) in the throttle valve control module over the full range of engine speeds and load conditions.
The throttle valve positioner actuates the throttle valve according to the commands it receives from the engine control module.
When the ignition is on and the engine is not running, the engine control module operates the throttle valve positioner in exact accordance with the signals from the accelerator position senders. For example, when the accelerator is pressed down half way, the throttle valve positioner opens the throttle valve by an equivalent amount, i.e. about half way.
--------------------------------------------------------------------------------
24-136
When the engine is running (i.e. under load) the engine control module can open and close the throttle valve freely (i.e. independently of the signals being sent by the accelerator position sender).
For example, the throttle valve might already be fully open even though the accelerator is only pressed down half way. This has the advantage of preventing throttling losses at the throttle valve.
Under certain engine load conditions there is also a significant reduction in harmful emissions and noticeably improved fuel consumption.
The engine control module can provide the optimum combination of throttle valve opening and charge pressure in order to create the required torque.
The electronic throttle is not simply a combination of two or three components, but rather a complete system comprising all the elements that together determine the position of the throttle valve and also control and monitor it. For example, the accelerator position sender, throttle valve control module, EPC warning lamp, engine control module etc.
--------------------------------------------------------------------------------
24-137
Electronic throttle warning lamp in instrument cluster
Note:
Electronic throttle warning lamp -K132 is also known as the EPC warning lamp (EPC = electronic power control).
"EPC" stands for Electronic Power Control and refers to the electronic throttle control system.
Fitting location of EPC warning lamp
When the ignition is switched on the engine control module tests all the components whose functions relate to the electronic throttle system.
The engine control module activates the EPC warning lamp when the ignition is switched on. The warning lamp will go out soon after the engine starts, provided that the engine control module does not detect any faults in the electronic throttle system and the activation of the lamp via the engine control module is working properly.
If a fault is detected in the electronic throttle system while the engine is running, the engine control module will activate the EPC warning lamp (see Fault Table for list of possible faults). At the same time a Diagnostic Trouble Code (DTC) is stored in the Diagnostic Trouble Code (DTC) memory of the engine control module.
Display Group 062: Electronic throttle potentiometer voltages
Display
xx %
xx %
xx %
xx %
Indicates
Throttle valve angle
(angle sender 1)
Throttle valve angle
(angle sender 2)
Accelerator position
sender 1
Accelerator position
sender 2
Specification
3 to 93 %
97 to 3 %
12 to 97 %
4 to 49 %
Note:
The engine control module converts the voltage readings from the angle senders into percentages of 5 V and displays them as percentages. (A supply voltage of 5 V is equivalent to 100%.)
- Observe display zones 1 and 2.
- Slowly depress accelerator to full throttle position.
The percentage value in display zone 1 should rise steadily between 3 and 93 % but without covering the full range of values.
The percentage value in display zone 2 should fall steadily between 97 and 3 % but without covering the full range of values.
--------------------------------------------------------------------------------
24-150
Notes:
The reason why the value in display zone 1 rises and the value in display zone 2 falls is because the potentiometers (angle senders) in the throttle valve control module work in opposite directions.
The percentage value for the first potentiometer increases as the voltage rises toward 5 V because the voltage at this potentiometer increases as the throttle valve opens.
The percentage value for the second potentiometer decreases as the voltage drops away from 5 V and toward 0 V because the voltage at this potentiometer decreases as the throttle valve opens.
- Press the button to exit from the function "08 - Read data block".
If the display values do not appear as described:
- Test voltage supply and wiring to throttle valve control module Page 24-151 . Pay particular attention to the connectors, which may have corroded or become detached.
- Test accelerator position senders Page 24-153 .
It's pretty involved!