12 Oxygen Sensor After TWC, Bank 1 - Open Circuit

P0140

12 Oxygen Sensor After TWC, Bank 1 - Open Circuit

Function
To diagnose the readiness for operation of the oxygen sensors, the position of the sensor voltage is evaluated (diagnosis is disabled in the case of certain faults or conditions).

Diagnosis conditions







The DME control module stores DTC P0140 when the sensor voltage is continuously between 400 mV and 500 mV for more than 400 seconds.

P0140:

NOTE:
- If DTC P1117 (oxygen sensor heating) is stored in the memory, correct this fault first and then check whether DTC P0140 is stored again.
- Diagnosis can be performed with the Porsche System Tester 2 in the Short test menu.

Wiring Diagram







Diagnosis Procedure

Part 1:

Part 2:

1 Check function of oxygen sensor.
1. Heat the oxygen sensors (road test car under load or run engine without load at high rpm).
2. Connect Porsche System Tester 2 or scan tool and read voltage of oxygen sensor 1 after TWC.

Display: Voltage fluctuations between 100 mV and 800 mV.
- Oxygen sensor OK.

2 Check wiring harness.
1. Remove oxygen sensor connector.
2. Connect special tool 9637 to wiring harness (DME control module connector).
3. With an ohmmeter, measure resistance between special tool 9637, pin II/11, and oxygen sensor connector, pin 3.

Display: 0 - 5 ohms

4. With an ohmmeter, measure resistance between special tool 9637, pin II/17, and oxygen sensor connector, pin 4.

Display: 0 - 5 ohms