P1275

P1275

Signal Delay Time for Oxygen Sensor Ageing, Bank 1 - Above/Below Limit

Function
The diagnosis of "oxygen sensor ageing" helps to identify oxygen sensors ahead of TWC that lead to emission limits being exceeded because of ageing.

The value of the higher-level I-controller is used to detect a shift in the sensor characteristic. Within the framework of the 2-sensor oxygen sensing system, this I-controller ensures that a level of emissions which conforms with regulations can also be achieved for a sensor with a characteristic shift via the delay time of the oxygen sensing system.

Diagnosis conditions
- No secondary air
- No diagnosis of secondary air system
- No fuel tank ventilation
- Oxygen sensing after catalytic converter is active
- No faults for misfire detection, throttle valve, oxygen sensor heating, camshaft position sensor, fuel tank ventilation system, EVAP canister purge valve output stage, voltage supply or mixture adaptation.

P1275 - P1276:

Diagnosis Procedure







1 Road test vehicle or perform short test.
1. Erase the fault memory.
2. Heat the oxygen sensors (road test car under load or run engine for 10 minutes without load at high rpm).
3. Road test vehicle or perform short test, ensuring that the diagnosis conditions are reached.
4. Read out the fault memory.

2 Read out regulator delay after TWC, banks 1 and 2.
Read out regulator delay with Porsche System Tester 2 or sensor characteristic shift with a scan tool in Mode 5.
Display: less then 1.2 or greater then 1.2 sec.