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P0131, P0132, P0133

Read the instructions below then start the fault diagnostic procedure.

Symptom: CHECK ENGINE lamp on. Possibly other diagnostic trouble codes (e.g. misfiring, closed loop, adaptation).

P0131, P0132, P0133


Oxygen Sensor. Lean / Short to Ground.

Front Heated Oxygen Sensor Circuit. Short to B+.

Front Heated Oxygen Sensor. Poor response to change in fuel-air mixture.


Fault symptoms

CHECK ENGINE lamp on. Possibly other diagnostic trouble codes (e.g. misfiring, closed loop, adaptation).

Conditions

P0131: Closed loop >25% for longer than 20 sec. Oxygen sensor 2 indicates rich mixture at the same time

P0132: Ignition ON. Sensor voltage >1500 mV for longer than 5 sec. Or, closed loop <-25% for longer than 20 sec. Oxygen sensor 2 indicates lean mixture at the same time

P0133: Diagnosis not yet performed during this trip.

• Longer than 3 min. since start

• Speed=0

• Idling speed.

• Closed loop active.

• Engine coolant temperature >60C (>140F).

• Oxygen sensor preheating current <1500 mA.

• Oxygen sensor voltage fluctuation frequency too low.

Diagnostic help

The function of the oxygen sensor can be read with the diagnostic tool.


- Select " Data Display / Output Control (New)".



- Select " O2S 1".


The diagnostic tool should fluctuate around 0.1 - 0.9 V when closed loop is active.

Both P0132 and P0138 are often generated if any of the oxygen sensor reference grounds or sensor voltage is short-circuited to B+ in the wiring harness or in any of the oxygen sensors.

The oxygen sensor control module inputs are high-ohmic. A diagnostic trouble code will be generated if moisture enters any of the oxygen sensor connectors.

Checking the wiring harness. Intermittent faults may occur in connection with short circuits and open circuits. Jiggle the wiring harness at several points and in several directions to locate any problems in the wiring, including intermediate connectors. Observe the multimeter, scan tool or test lamp during the check.