P1124

P1124
Oxygen Sensing Adaptation Range 1 (Cylinder 1 - 3) Enrichment Limit.

P1126
Oxygen Sensing Adaptation Range 1 (Cylinder 4 - 6) Enrichment Limit.

Function:
The adaptive oxygen sensing corrects longer lasting deviations of the fuel/air mixture from lambda = 1 through changes of the calculated pilot control within the engine control module and with that the injection time.
Should the correction factor through adaptation exceed a predetermined value, the diagnosis will detect the adaptation limit.

Range 1 covers the engine operating state close to idle.

Diagnostic Conditions:
- Oxygen sensing is active.
- Time elapsed after engine start-up 250 to 350 seconds.
- Engine temperature >62°C.
- Intake air temperature < 90°C.
- Air mass flow < 29 kg/h
- Engine speed < 880 rpm

NOTE:
If DTC P1124 or P1126 (oxygen sensing at enrichment limit) is in the memory, this means that the fuel/air mixture is too lean.
Leakage air ahead of the oxygen sensors can also lead to a fault in adaptation.

Diagnostic Procedure:



1. Checking fuel pressure.



1. Undo covering cap on test connection of fuel collection pipe and remove.
2. Connect pressure gauge (special tool P 378a) with connecting line (special tool 9559) and connect to test connection.



3. Actuating fuel pump

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

- via fuel-pump relay without Tester.
Disconnect fuel-pump relay from the central electrical board and bridge contacts 30 and 87 (identified as 3 and 5 on the central electrical board) 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 (2.0 ± 0.5 ft. lbs.).

2. Checking volume supply of fuel pump.
Precondition:
Fuel filter and electrical supply in order.



1. Relieve pressure in fuel tank by opening tank cap.
2. Connect Porsche System Tester 2.
3. Raise vehicle.
4. Remove rear underside panel.
5. Disconnect fuel return line. Collect residual fuel.



6. Hold fuel line in a measuring container. Actuate fuel pump with the Porsche System Tester 2 and allow fuel to flow for 30 seconds into a measuring container.
Quantity supplied must be at least 850 cm cube/30 s, i.e. after 30 seconds at least 850 cm cube of fuel must be present in the measuring container.

NOTE: Always observe safety regulations.

3. Fuel injectors contaminated (carbonized).
1. If checkpoints are negative, the fuel injectors may be contaminated (carbonized).
2. Clean fuel injectors (ultrasound cleaning device) or replace.