Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information

Condition
Engine control module (ECM) calculates the air mass in to the engine with. among other, information about the throttle's position, engine rpm, air temperature and atmospheric pressure. The calculated air mass is then used to check the signals from the mass air flow sensor and the intake manifold pressure sensor. If Engine control module (ECM) registers that the signal from any of these two sensors deviates sufficiently from the calculated air mass, then diagnostic trouble code ECM-980F, Faulty flow, is stored.
For upgraded software, released during year 2006 or later, the diagnostic trouble code will only be stored when the measured air mass from the mass air flow sensor is sufficiently greater than the calculated air mass.

Substitute value

Closing of throttle during braking.
The accelerator pedal position is ignored when the brake pedal is depressed.

Cruise control off.
Cruise control off during entire operating cycle in which fault was detected. If the fault is no longer present, the function is available the next time the car is started.

Fuel cut-off that follows accelerator pedal position.
Engine speed is regulated via fuel cut-off by deactivating the injectors one at a time. Engine speed is determined by gas pedal position sensor position and engine speed is maximized to about 5000 rpm. This reconfiguration can cause the engine to idle very unevenly since the engine control module (ECM) regulates engine speed by cutting of the fuel to the cylinders individually. Do not confuse this reconfiguration (engine behavior) with an actual driveability problem that was present before reconfiguration.
For upgraded software, released in 2006 or later, adjustments have been made to substitute values. In the driving cycles where the fault is active, except the above replacement values, then fuel shut-off which also follows the accelerator pedal position will be active and it will not be able to activate cruise control.

Possible source

Faulty signal:
- the exhaust camshaft has jumped off the cogs
- air leak downstream of the mass air flow (MAF) sensor
- defective manifold absolute pressure (MAP) sensor
- defective mass air flow (MAF) sensor
- defective engine control module (ECM).
This diagnostic trouble code is generated in combination with other trouble codes. Information on the possible root cause is described.

Fault symptom[s]
- uneven idle
- malfunction indicator lamp (MIL) lit.