P1140

P1140
Load Calculation - Signal implausible

Function
A load signal is generated to determine the engine load. This signal is calculated from the intake air mass (signal from the mass air flow sensor) and the engine speed. This load signal is corrected by the intake air temperature and a taught altitude factor for the purpose of adaption to the air density.

Diagnostic conditions
- Engine at idle.
- Throttle valve angle between 100 and 600.
- No fault in mass air flow sensor.
- No fault in throttle position sensor.
- No fault in idle air control valve.
- Time after engine start-up > 240 seconds.
- Time for fault detection > 25 seconds.





Diagnostic Procedure
Readjust operating cable for cruise control.

Pre-requisite: Throttle in stop position and operating cable for throttle load-free.

Basic adjustment:
1. Remove rear fan.




2. Slacken lock nut on operating cable for cruise control (wrench size 5.5).





3. Adjust operating cable to obtain a 1 mm distance between the operating cable support and the hexagon head nut in rest position.
4. Counter hexagon nut again.

Read specified values for Throttle Position Sensor.
1. Connect system tester.
2. Switch to menu point "Specified values".
3. Select Throttle Position Sensor.
4. Read specified value for closed Throttle Position Sensor.
- Specified value: approximately 0 %
5. Fully depress accelerator pedal
6. Read specified value for wide open Throttle Position Sensor.
- Specified value: approximately 75 %

NOTE: It is important, that the value changes and not stay with one value.








Check air intake system for leaks.
1. Remove air cleaner cover and insert.




2. Undo hose clamp on mass air flow sensor with a cross-head screwdriver, e.g. from Messrs. With Order No. 153-1(350 mm long).




3. The restricted space available necessitates separation of the mass air flow sensor and air cleaner housing in the engine compartment. To remove, turn the mass air flow sensor in the direction of the arrow (driving direction), at the same time countering at the air cleaner housing (bayonet lock).








4. Lever off circlip and remove protective grille.
5. Secure sealing plate 9264/1 on mass air flow sensor using screws M 4 x 40 and washers.

NOTE: Check the position of the mass air flow sensor on the sealing plate before finally tightening the Screws i.e. no light gap must be visible upon inspection.








6. Build up a pressure of approx. 0.5 bar. Large leaks are very audible when the pressure has been built up; small leaks can be made visible using leak spray.

NOTE: The pressure relief valve on the oil tank opens at 180 +/- 20 mbar. Block the valve. To do this, remove the front wheel housing liner of the right rear wheel housing. Close off the hose from the oil tank pressure relief valve with a suitable stopper.

- Remove the stopper from the hose after carrying out the leak test.
- Assemble the mass air flow sensor and air cleaner housing in the engine compartment before attaching the mass air flow sensor to the air intake system.