Diagnostic trouble code (DTC) information

Condition 

The control module receives information from the heated oxygen sensor (HO2S) about the fuel / air mixture. If the fuel / air mixture deviates from λ=1, the short-term fuel trim will compensate for this by adjusting the injection time so that λ=1 is achieved. Diagnostic Trouble Code (DTC) ECM-268A will be stored if the short-term fuel trim deviates too much from its central position (value) when the long-term fuel trim diagnostics are activated.

Substitute Value 

none

Possible Source 

Upper limit 

• intake air leakage
• exhaust system air leakage
• low fuel pressure
• defective heated oxygen sensor (HO2S)

Lower limit 

• intake air leakage
• high fuel pressure
• leaking injectors
• defective mass air flow (MAF) sensor
• contaminated engine oil
• oil level too high
• defective heated oxygen sensor (HO2S)

Fault symptom[s] 

• none