358 Oxygen Sensing Adaptation, Lower Load Range, Bank 2 - Above Limit

P1133

358 Oxygen Sensing Adaptation, Lower Load Range, Bank 2 - Above Limit

Function
The adaptive oxygen sensing system corrects longer lasting deviations in the fuel/air mixture from lambda = 1 by changing the anticipatory control calculated in the DME control module and the injection timing altered as a result. Should the correction factor through adaptation exceed a predetermined value, the diagnosis will detect the adaptation threshold.

Diagnosis conditions
- Oxygen sensing system active
- Time elapsed after
engine start-up:
250 to 350 seconds (USA)
302 to 402 seconds (RoW)

- Engine temperature > 62 °C
- Intake air temperature < 90 °C
- Air mass flow between 40 kg/h and 140 kg/h
- Load signal between 18 % and 80 %

P1126 - P1133:

NOTE: Air leaks ahead of the oxygen sensors can lead to a fault in adaptation. Check exhaust system for leaks.

If the fuel tank reserve light is switched on, no fault is entered.

Diagnosis Procedure

Part 1:

Part 2:

1 Check signal from MAF sensor.
1. Connect special tool 9637.
2. Connect voltmeter to pin III/23 and ground.

Switch on the ignition.
Display: 0.9 to 1.1 V

Start engine.
Display: approx. 1.4 V

2 Check fuel pressure.







1. Undo and remove the closure cap of the fuel collection pipe test connection (A/F 13 mm).
2. Connect pressure gauge (special tool P 378a) to connecting line (special tool 9559) and connect to test connection.
3. Actuate fuel pump, either

- with Porsche System Tester 2
The fuel pump can be actuated with the Porsche System Tester 2 or by jumpering the fuel pump relay.

or







- via fuel pump relay without tester
Disconnect the fuel pump relay from the central electrical system and jumper plug-in contacts 30 and 87 (identification 3 and 5 on central electrical system) with a fused shop-made cable. The fuel pump must now operate or deliver fuel.

4. Nominal test values

Stationary engine 3.8 ± 0.2 bar
Engine idling 3.3 ± 0.2 bar

NOTE: The seal or sealing ring in the brass closure cap is not exchangeable. It must therefore be used only once.

Tightening torque of new brass closure cap 2.5 ±0.5 Nm.

3 Check volume supply of fuel pump.







Precondition:
Fuel filter and electrical supply OK.
1. Relieve pressure in fuel tank by opening tank cap.
2. Connect Porsche System Tester 2.
3. Remove complete air filter system.
4. Detach fuel return line from the engine compartment, taking care to hold it fast. Collect residual fuel.







5. Connect fuel hose (shop-made, approx. 1.5 m long) to the fitting and hold in a measuring container.
6. Actuate fuel pump with the Porsche System Tester 2 and allow fuel to flow into the measuring container for 30 seconds.

Quantity supplied must be at least 850 cm3/30 s, i.e. after 30 seconds at least 850 cm3 of fuel must be in the measuring container.

NOTE: It is essential to observe safety regulations for handling fuel.

4 Fuel injectors fouled.
1. If preceding Check Points were negative, the fuel injectors may be fouled.
2. Clean fuel injectors (ultrasonic cleaning device) or replace them.