DTC 2-3-1

ED. Fault code 2-3-1 and 2-3-2 Regina

2-3-1 Adaptive lambda control too lean / rich in part load range

Conditions for fault code:
The adaptive system has compensated for slow changes in the fuel/air ratio.
The control unit receives information from the lambdasond if the fuel/air mixture is too rich or too lean in the partial load area. The adaptive system compensates by enrichening or diluting the mixture to maintain lambda=1, which is the correct fuel/air ratio. When the adaptive system has compensated almost as much as it can, this is interpreted as abnormal and fault code 2-3-1 is set.

Causes of fault:
1. Engine runs too lean:
Air leakage.
Low fuel pressure.
Faulty sensor signals
2. Engine runs too rich:
High fuel pressure.
Contaminated engine oil.
Leaking injector.
Leaking EVAP valve.
Faulty sensor signals.

Fault symptom:
Engine dies at cold starts.
Possible high fuel consumption.
Various driveability problems.

2-3-2 Adaptive lambda control too lean / rich when idling

Conditions for fault codes:
The adaptive system has compensated for swift changes in the fuel/air mixture.
The control unit receives information from the lambdasond if the fuel/air mixture is too rich or too lean at idling speed. The adaptive system compensates by enrichening or diluting the mixture to maintain lambda=1, which is the correct fuel/air ratio. When the adaptive system has compensated almost as much as it can, this is interpreted as abnormal and fault code 2-3-2 is set.

Fault causes and fault symptoms:
See above.

ED1




Checking of signal from lambdasond
- Start the engine.
Connect a voltmeter between 1 (1-pole connector at fire- wall) and ground.



The voltmeter reading should vary between 0.1 V and 1.2 V.

If the voltmeter reading is OK:
^ Sond signal is OK ED2.

If the voltmeter mostly shows a low value:
^ Sond signal mostly low ED3.

If the voltmeter mostly shows a high value:
^ Sond signal mostly high ED4.

ED2

Sond signal OK
Even if the signal is correct upon measurement the adaptive system may have compensated for a fault
^ Continue with Deletion of fault code ED5.

ED3

Sond signal mostly low
The sond's signal to the control unit indicates that the fuel/air mixture is too lean. This may be because of air leakage, low fuel pressure or an incorrect signal from one of the sensors (pressure sensor, air temperature sensor etc.).
^ Continue with Deletion of fault code ED5.

ED4

Sond signal mostly high:
The sond's signal to the control unit indicates that the fuel/air mixture is too rich. This may be because of excessively high fuel pressure, leakage in the cold start injector, diluted engine oil, leaking EVAP valve or incorrect signal from one of the sensors (pressure sensor, air temperature sensor etc.).
^ Continue with Deletion of fault code ED5.

ED5




Deletion of fault codes
Delete any fault codes in the fuel system according to D. Troubleshooting via the diagnostic socket. Bendix System [Regina/Rex-I]
^ Continue with Connection of CO & HC-meter ED6.

ED6




Connection of CO & HC-meter

Important! The CO connection can be extremely hot!

- Connect the CO-meter with connector 5410 to the CO- outlet near the catalyst.
- Run the engine until warm.
^ Continue with Resetting adaption ED7.

ED7




Resetting adaption
In order to reset adaption the sond signal must have remained unchanged for at least 3 minutes and fault code 2-2-1 must be checking function 1.
- Disconnect the 1-pole connector from the lambdasond at the firewall.
- Let the engine run at idling speed until the environment lamp lights up, approx. 3 minutes.

With the sond disconnected, the CO-value will be 6-8 % before fault code 2-2-1 is set.

Important! If the engine's load changes or if the engine stops, adaption resetting must be performed once again.

^ Continue with Checking of default CO and HC values ED8.

ED8




Checking of default CO and HC values
- Read off default CO and HC values.
The CO-content shall be 0.4-0.8 %.
The HC-value shall be less than 400 ppm.

1. If the default CO and HC values are OK:
^ Connection of measurement box ED13.
Check with extra care the incoming signals with regard to connection resistance.
2. If the HC-value is too high:
^ Check the ignition coil, ignition cables, rotor and spark plugs.
3. If the default CO is too high:
The engine is running too rich.
^ Default CO too high ED9.
4. If default CO too low:
The engine is running too lean.
^ Default CO too low ED12.

ED9




Default CO too high
- Warm up the engine.
- Disconnect and plug the crankcase ventilation.
- Read off the CO content.

If the CO content drops to 0.4-0.8 %:
This indicates that the engine oil is mixed with fuel.
^ Replace the engine oil.
^ Replace the oil filter.

If the CO content is still high:
^ Check of fuel pressure ED10.

ED10




Check of fuel pressure
- Connect the 1-pole connector.
Check the fuel pressure and residual pressure according to S. Fuel pressure and residual pressure. S. Fuel Pressure and Residual Pressure

If fuel and residual pressure are OK:.
^ Check of EVAP system ED11.

ED11




Check of EVAP system.
^ Check the EVAP system according to T. Check the EVAP system. T. Checking the EVAP System

If the EVAP system is OK:
^ Connection of measurement box ED13.

ED12




Default CO too low
- Connect the 1-pole connector.
Check the fuel pressure and residual pressure according to S. Fuel pressure and residual pressure. S. Fuel Pressure and Residual Pressure

If fuel and residual pressure are OK:
^ At high Idle speed: U. Air and vacuum hoses. U. Checking the Air and Vacuum Hoses
^ If there is no air leakage and at normal idle speed:
^ Connection of measurement box ED13.

ED13




Connection of measurement box
Connect the measurement box to Regina and check the chassis connections according to N1-N2. N. Measurement Box, Signal Description
^ Continue with Checking of input and output signals ED14.

ED14




Checking of input and output signals
- Connect the control unit to the measurement box
- insert fuse 1.
Carry out the measurements with ignition on and at idle speed.




Check the following signals and compare with the nominal values. See NB. Signal description Regina, NB. Signal Description Regina
^ Ground temperature and pressure sensor #6
^ Pressure sensor #7 and #11
^ Temp. sensor air #10
^ Temp. sensor engine #13