DTC 1-2-1

EE. Fault code 1-2-1 Regina

* 1-2-1 Pressure sensor signal absent or faulty



Conditions for fault code:
If the signal has an abnormally high or low value, the fault code is set.
If the signal from the pressure sensor is missing, the control unit compensates with fixed values (limp-home facility) so that the car can still be driven.
The fault code is set and the Check Engine lamp lights up.

Causes of faults:
Breakage or short circuit to ground in wires, connections or pressure sensor. Connector resistance in connections. Poor chassis connection of signal ground.

Fault symptom:
Poor acceleration. The engine cuts out at idling speed. Difficulty in starting when hot and cold.

REGINA #7 Pressure sensor signal missing



Conditions for fault message:
The fault message is stored if the voltage is less than approx. 0.2 volts.

Cause of fault:
Break or short circuit to ground in wiring between Regina #7 and pressure sensor.
Break in wiring between Regina #11 and pressure sensor.

Fault symptoms:
See above.

REGINA #11 Air pressure faulty



Conditions for fault message:
Fault message is stored if voltage is less than approx. 1 V.

Causes of faults:
Short circuit to ground in the wiring between Regina #11 and the pressure sensor.

Fault symptoms:
See above.

EE1




Checking of voltage supply
- Disconnect the pressure sensor.
- Ignition on.
Connect a voltmeter between C in the connector and ground.
The voltmeter should show approx. 5 V.

If the value is OK:
^ Connection of measurement box EE2.

If the value is different:
No voltage supply to the pressure sensor.
^ Connection of measurement box EE2.

EE2




Connection of measurement box
Connect the measurement box to Regina and check the chassis connections according to N1-N2.
Check with extra care the chassis connections to #5 on the control unit.
^ Continue with Checking of resistance to ground EE3.

EE3




Checking of resistance to ground
- Ignition off.
- Sensor disconnected.
Connect an ohmmeter between #11 and #5 (ground).
The ohmmeter should show infinite resistance.

If the value is OK:
^ Checking of chassis connection EE5.

If the value is different:
^ Check the wiring between #11 and the sensor for signs of short circuit to ground.

EE5




Checking of chassis connection
- Connect the control unit to the measurement box.
- Ignition off.
- Sensor disconnected.
Connect an ohmmeter between #6 and #5 (ground).
The ohmmeter should show approx. 0 ohms.

If the value is OK:
^ Checking the voltage to pressure sensor EE6.

If the value Is different:
^ Check the tab on #5 and #6 with regard to connector resistance according to CD. CD. Checking of Wiring

EE6




Checking of voltage to pressure sensor
- Connect the sensor.
- Insert fuse no. 1.
- Ignition on.
Connect a voltmeter between #6 and #11.
The voltmeter should show approx. 5 V.

If the value is OK:
^ Checking the signal from pressure sensor EE7.

If the value is different:
^ If EE1 gave a different value:
Check the wiring between #11 and the pressure sensor for signs of breakage according to CD.

^ If EE1 was OK:
Test with a new control unit.

EE7




Checking the signal from pressure sensor
- Ignition on.
Connect a voltmeter between #6 and #7.
The voltmeter should show approx. 4.5 V.

If the value is different:
^ Check the wiring between #7 and the pressure sensor for signs of breakage and short circuit to ground according to CD. CD. Checking of Wiring




- Start the engine.
The voltmeter should show 1.2-1.4 V at idling speed.

If both the values are OK:
Intermittent fault.
^ Check the connectors with regard to loose connections.

If the value is different:
^ Test with a new pressure sensor.