DTC 3-4-4

ER. Diagnostic trouble code (DTC) 3-4-4 MFI LH 2.4

3-4-4 EGR temperature signal absent or faulty(B 204 FT/GT)



DTC conditions:
The control module receives information from the EGR temperature sensor about the temperature of the exhaust gases. Using this information the control module can check the fuel/air mixture when the engine is working hard. If necessary it can also lower the temperature of the exhaust gases. The DTC is logged when a certain load has been reached but no information about the exhaust gas temperature is reaching the control module.

Causes of fault:
Breaks, grounding or short circuits in the EGR temperature sensor.

Fault symptoms:
High fuel consumption. Overheating in the TWC.

ER1




Resetting the diagnostic trouble codes (DTCS)
- Read and delete the DTCs.
- Start the engine and let it run for about one minute.

If the DTC recurs:
^ Check the EGR temperature sensor connections to GND ER2.

If the DTC does not recur:
Intermittent fault.
^ Check the EGR temperature sensor connections and wiring for loose contacts In accordance with NA5 and clean the EGR temperature sensors connector and treat it for corrosion in accordance with NA7. NA. Checking the Wiring

ER2




Checking the EGR temperature sensor connections to GND
- Disconnect the EGR temperature sensor.
- Ignition off.
Connect an ohmmeter between terminal 2 in the EGR temperature sensor connector and GND (the intake manifold)
The ohmmeter should read 0 ohms.

It this value is OK:
^ Check the power supply ER3.

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

ER3




Check the power supply
- Ignition on.
Connect a voltmeter between terminal 3 in the EGR temperature sensor connector and GND.
The voltmeter should read battery voltage.

It this value is OK:
^ Connect the test box ER4.

If the reading is incorrect:
^ Check the wiring between terminal 3 in the EGR temperature sensor connector and the battery for breaks to the ignition switch in accordance with NA2. NA. Checking the Wiring

ER4




Connecting the test box
Connect the test box to MFI and check the GND points in accordance with P1-P2. P. Test Box, Signal Description
^ Continue with Checking the signal wiring ER5.

ER5




Checking the signal wiring
- Ignition off.
Connect an ohmmeter between #28 and #5 (GND).
The ohmmeter should read infinite resistance.

If this value is OK:
^ Check the resistance in the wiring ER6.

If the reading is incorrect:
^ Check the wiring to #28 on the control module for short circuits in accordance with NA3. NA. Checking the Wiring

ER6




Checking resistance in the wiring
Connect an ohmmeter between #28 and #1 in the EGR temperature sensors connector.
The ohmmeter should read 0 ohms.

If this reading is OK:
^ Check the EGR temperature sensor ER7.

If this value is incorrect:
^ Check the wiring to #28 on the control module for grounding in accordance with NA3. NA. Checking the Wiring

ER7




Checking the EGR temperature sensor
- Connect the control module
- Install fuse 1 (or 31).
- Connect the EGR temperature sensor.
- Start the engine.
Connect a voltmeter between #5 and #28.
The voltmeter should read approx. 0.7 V AC (approx. 11.3 Hz).

If this value is OK:
Intermittent fault.
^ Check the wiring for contact resistance In accordance with NA8, clean the connector and treat it for corrosion in accordance with NA7. NA. Checking the Wiring

If the reading is incorrect:
^ Try using a new EGR temperature sensor.
^ Clean the connector and treat It for corrosion in accordance with NA7. NA. Checking the Wiring