Diagnostic trouble code (DTC) information
Condition
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 control module interprets it as a fault and ECM-1200 is stored.
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:
- open-circuit in the signal cable
- short-circuit to supply voltage in the signal cable
- defective mass air flow (MAF) sensor
- open-circuit in the ground lead
- contact resistance in terminals
Fault symptom[s]
- Malfunction indicator lamp (MIL) lit.