Diagnostic trouble code (DTC) information

Condition 

The control module controls preheating by pulsing the current to the PTC-element. Pulse lengths are dependent on heated oxygen sensor (H02S) temperature.

Diagnostic trouble code (DTC) ECM-2A2A is stored if the control module registers that the signal is constantly 2. 5 V, higher than 3. 5 V at current pulse or lower than 2. 3 V at no pulse.

The control module also registers the heated oxygen sensor (H02S) temperature by measuring resistance in the PTC-element. The probe temperature is then compared with a calculated temperature.

Diagnostic trouble code (DTC) ECM-2A2A is stored for a faulty signal if the control module registers that the actual probe temperature is lower than the calculated temperature.

Substitute Value 

• fuel trim shut off.

Possible Source 

Signal too high: 

• short-circuit to supply voltage in the signal cable
• defective heated oxygen sensor (HO2S).

Signal too low: 

• short-circuit to ground in the signal cable
• defective heated oxygen sensor (HO2S).

Signal missing: 

• contact resistance and oxidation
• open-circuit in power supply from system relay.

Faulty signal: 

• defective heated oxygen sensor (HO2S).

Fault symptom[s] 

• MIL-lamp lights.