Diesel Data: Automotive Repair

Fault Conditions




P0131


O2S Circuit. Low Voltage. Sensor 1.







Fault symptoms
- CHECK ENGINE.
- Misfiring can occur before trouble code is generated.

On-Board Diagnostics

Type of diagnosis:
- Continuous. But interrupted when fault criteria fulfilled and will not restart until next driving cycle.

Enable criteria:
- General conditions for this trouble code: Atmospheric pressure must exceed 72 kPa and the engine coolant and intake air temperatures must exceed -7°C.
- Engine running. Main relay voltage exceeding 10 V. Oxygen sensor 2 voltage exceeding 0.700 V.

Fault criteria:
- Voltage below 0.025 V for more than 15 s.

Dependents:
- P1135 and P1136.

System reactions to a fault
- Closed loop is blocked.

OK report:
- P0134 Test 1 and Test 2 performed once and fault criteria not fulfilled. 60 s has expired and closed loop still active. Fault criteria for P0131 or P0132 not fulfilled.

Fault handling: (See "Fault diagnosis, general" for more information.) Initial Inspection and Diagnostic Overview
- Type III.

Diagnostic help
Fault diagnosis concerns an electrical fault in connecting leads or in the sensor.

Functions in the diagnostic tool related to the fault:
- Diagnostic status for the diagnosis.
- Oxygen Sensor Value, unit V.

See also description of read values in Menu "Read Values" for more information. Tech 2 Menu Structure, DTC Menu, Read Value, Activate, Sys Info


NOTE: Oxygen sensor receives reference oxygen from the surrounding air via the connecting cables. For this reason, electrical contact spray or grease must not be used on the oxygen sensor connector.


Checking the wiring
Jiggle the wiring harness at several points and in different directions to detect intermittent breaks and short circuits. Observe the multimeter, diagnostic tool or test lamp during the check.