Diagnostic trouble code (DTC) information ECM-1200
Condition
Diagnostic trouble code (DTC) ECM-1200 is stored if the engine has been running for 3 minutes and been idling for at least 60 seconds and the control module receives a signal from the intake air temperature sensor (integrated in the mass air flow (MAF) sensor) corresponding to a temperature lower than -29 °C or higher than +129 °C. The diagnostic trouble code (DTC) is also stored if the signal is abnormal for the air temperature sensor.
Substitute Value
+20 °C
Three-way catalytic converter (TWC) preheating and idle air trim diagnostics are disabled.
Possible Source
Signal too high:
- Short-circuit to ground in the signal cable
- Defective mass air flow (MAF) sensor.
Signal too low:
- Contact resistance or oxidation in the terminals
- Open-circuit in the signal cable
- Open-circuit in the signal ground cable
- Short-circuit to supply voltage in the signal cable
- Defective mass air flow (MAF) sensor.
Faulty signal:
- Contact resistance or oxidation in the terminals
- Defective mass air flow (MAF) sensor.
Fault symptom[s]
- Malfunction indicator lamp (MIL) lit
- Poor performance.