Diagnostic trouble code (DTC) information
Condition
The signal from boost pressure sensor 1 is checked if no fault is detected in the throttle position (TP) sensor or idle air control (IAC) valve by the control module. Diagnostic trouble code (DTC) ECM-AC is stored if the control module detects that the signal from boost pressure sensor 1 is lower than a lower limit (signal too low) at an engine speed lower than 800 RPM or higher than an upper limit (signal too high) when the throttle is closed and the engine speed is above 1000 RPM.
Substitute Value
No leak diagnostic.
1013 mbar at start.
The signals from the intake air temperature (IAT) sensor, the throttle position (TP) sensor, the engine speed (RPM) sensor and boost pressure sensor 2 are used to calculate the boost pressure 1 while driving.
Possible Source
Signal too high:
- Short-circuit to supply voltage in the signal cable
- Open-circuit in the ground lead
- Defective boost pressure sensor 1.
Signal too low:
- Contact resistance in the terminals
- Open-circuit in the signal cable
- Short-circuit to ground in the signal cable
- Open-circuit in the power supply cable for boost pressure sensor 1
- Defective boost pressure sensor 1.
Fault symptom[s]
- Malfunction indicator lamp (MIL) lit
- Uneven idle.