DTC 2-2-1

EK. Diagnostic trouble code (DTC) 2-2-1 MFI LH 2.4

* 2-2-1 Adaptive fuel trim too lean at part loads

If DTC 1-1-3 is logged at the same time as other DTCs, the first code to be presented by the OBD system should be remedied first. The following DTCs are regarded as secondary faults.




DTC conditions:
The adaptive system compensates for gradual changes in the fuel/air mixture.
The control module receives information from the HO2S if the fuel/air mixture is too lean at pant loads. The adaptive system compensates for this by enriching the fuel/air mixture in order to maintain lambda=1, which is the correct fuel/air mixture. When the adaptive system has almost compensated as much as it can this is interpreted as abnormal and DTC 2-2-1 is logged.

Causes of fault:
Mixture too lean, air leak, low fuel pressure, faulty sender signals.

Fault symptoms:
Engine stops running when starting from cold, fuel consumption too high, various driving problems.

EK1




Checking the air and vacuum hoses
^ Check the air and vacuum hoses in accordance with Z. Checking the air and vacuum hoses. Z. Checking the Air and Vacuum Hoses

If the air and vacuum hoses are OK:
^ Check the exhaust system EK2.

If air and vacuum hoses are defective:
^ Remedy as necessary.

EK2




Checking the exhaust system
^ Check the exhaust system in accordance with BE. Mechanical inspection. BE. Mechanical Overview

If the exhaust system is OK:
^ Check the MAF sensor GND point EK3.

If the exhaust system is leaking:
^ Remedy as necessary.

EK3




Checking the mass air flow (MAF) sensor GND point
- Ignition off.
- Disconnect the connector from the MAF sensor.
- Connect an ohmmeter between terminal 1 in the connector and GND.
The ohmmeter should read approx. 0 ohms.

If this value is OK:
^ Check the signal from the MAF sensor EK4.

If the reading is incorrect:
^ Check the GND terminal on the intake manifold for contact resistance in accordance with NA6. NA. Checking the Wiring

EK4




Checking the signal from the mass air flow (MAF) sensor
- Clean the MAF sensor connector and treat it for corrosion in accordance with NA7. NA. Checking the Wiring
- Start the engine.
Connect a voltmeter between terminal 3 on the back of the MAF sensor connector and GND.
The voltmeter should read approx. 2.3 volt.

If this value is OK:
^ Check the fuel pressure and residual pressure EK5.

If the reading is incorrect
^ Try using a new MAF sensor.

EK5




Checking the fuel pressure and residual pressure
^ Check the fuel and residual pressure in accordance with X. Fuel pressure and residual pressure. X. Fuel Pressure and Residual Pressure

If fuel pressure and residual pressure are OK:
^ Continue with Connecting the test box EK6.

EK6




Connecting the test box
Connect the test box to MFI and check the GND points in accordance with P1-P2.
^ Continue with Checking the input and output signals EK7.

EK7




Checking the input and output signals
- Connect the control module to the test box.
- Install fuse 1 (or 31).
Take readings with the ignition on and the engine idling.




Check the following signals and compare them with the values in PB. Signal description MFI LH 2.4: PB. Signal Description MFI LH 2.4
^ GND MAF sensor #6
^ Signal MAF sensor #7
^ If values are incorrect, check for contact resistance in the connections in accordance with NA6. NA. Checking the Wiring