DTC 4-1-3
4-1-3 EGR TEMPERATURE SENSOR SIGNALPreconditions for DTC
^ In order for the EGR diagnosis to be active, it is necessary that (a) the car is STARTED at an Engine Coolant Temperature (ECT) higher than -10°C (-14°F), (b) the car engine was switched OFF last time at an ECT higher than +8O°C (176°F), (c) battery voltage is above 12 Volts and (d) the Engine Coolant Temperature (ECT) sensor is undamaged. If the voltage across the EGR temperature sensor exceeds 4.4 Volts when the sensor is hot (high signal), is lower than 0.1 Volts when the sensor is cold (low signal) or varies considerably (faulty signal), the ECM interprets this as a fault and DTC 4-1-3 is set.
Substitute value
^ Long term fuel trim is inhibited.
^ Idle air trim is inhibited.
^ Only initial charge pressure is permitted.
Fault sources
^ Signal too high:
- Signal or ground lead short circuited to voltage supply.
- Break in signal or ground lead.
- Loose contact or contact resistance in connectors.
- Defective EGR temperature sensor.
- Flow fault in the EGR system.
^ Signal too low:
- Signal lead short circuited to ground.
- Defective EGR temperature sensor.
^ Faulty signal:
- Loose contact or contact resistance in connectors.
- Defective EGR temperature sensor.
Fault symptoms
^ Poorer performance from initial charge pressure limit.
TESTING PROCEDURE
CAUTION: When the DTC has been erased after fault tracing, the engine must be restarted twice in order to read the correct EGR temperature with the Volvo System Tester Scan Tool (ST).
Other DTCs
^ Read off the other DTCs.
If DTC 1-5-4 is stored:
- See: Testing By Trouble Code, DTC 1-5-4 EGR System Leakage.
If DTC 1-5-4 is not stored:
- Check Status message.
Status Message
^ Check current status message.
If Status message is: Signal Too High:
- Proceed to: SIGNAL TOO HIGH section below.
If Status message is: Signal Too Low:
- Proceed to: SIGNAL TOO LOW section below.
If Status message is: Faulty Signal:
- Proceed to: FAULTY SIGNAL section below.
SIGNAL TOO HIGH
Checking the EGR Controller
^ Switch Ignition ON.
^ Use Diagnostic Test Mode (DTM) 3 to check that the EGR controller functions.
If the EGR controller functions:
- Check EGR flow.
If the EGR controller does not function:
- Check voltage supply to the EGR controller.
Checking of EGR Flow
^ Switch Ignition OFF.
^ Undo the lead which is coupled to connector 2 on the EGR controller.
^ Connect a free lead to connector 2 on the EGR controller.
^ START the engine and let it run at idling speed.
^ Connect the free lead to ground (engine block).
The engine should now run unevenly at idling speed.
If the engine runs unevenly at idling speed:
- Check the EGR temperature sensor signal.
If the engine does not run evenly at idling speed:
- Check the vacuum in the EGR controller.
Checking the EGR Temperature Sensor Signal
^ Engine at idling speed.
^ Look up the DTC parameter list.
^ Check that the EGR temperature which is shown in the Volvo System Tester is reasonable.
^ Connect the free lead to ground and observe the voltage at the EGR temperature sensor.
Voltage should drop when the engine runs unevenly.
If the EGR temperature sensor signal is OK:
- The fault is intermittent.
- Proceed to: INTERMITTENT FAULT, SIGNAL TOO HIGH section below.
If the EGR temperature signal is not OK:
- Check the ground lead.
Checking the Ground Lead
^ Switch Ignition OFF.
^ Disconnect the EGR temperature sensor.
^ Switch Ignition ON.
^ Connect a voltmeter between the EGR temperature sensor's connector 2 (on the ECM) and ground.
The voltmeter should show 0 Volts.
If the reading is OK:
- Check the ground lead resistance to ground.
If the reading is incorrect:
- Check the lead between EGR temperature sensor connector 2 and ECM A18 for signs of short circuiting to voltage supply.
Checking the Ground Lead's Resistance to Ground
^ Switch Ignition OFF.
^ Wait for approx. 150 seconds.
^ EGR temperature sensor disconnected.
^ Connect an ohmmeter between EGR temperature sensor connector 2 (on the ECM) and ground.
The ohmmeter should show approx. 0 ohms.
If the reading is OK:
- Check the signal lead.
If the reading is incorrect:
- Check the ECM connector.
Checking the ECM Connector
^ Switch Ignition OFF.
^ EGR temperature sensor disconnected.
^ Rectify the ECM's connector with regard to contact resistance and oxidation.
^ ECM connected.
^ Connect an ohmmeter between EGR temperature sensor connector 2 (to ECM) and ground.
The ohmmeter should show approx. 0 ohms.
If the reading is OK:
- The source of the DTC is poor contact in the ECM connector.
If the reading is incorrect:
- Check the lead between EGR temperature sensor connector 2 and ECM A18 for signs of a break.
Checking the Signal Lead
^ Switch Ignition ON.
^ EGR temperature sensor disconnected.
^ Connect a voltmeter between EGR temperature sensor connector 1 (towards the ECM) and ground.
The voltmeter should show approx. 5 Volts.
If the reading is OK:
- Check the EGR temperature sensor.
If the reading is above 5 Volts:
- Check the lead between EGR temperature sensor connector 1 and ECM A35 for signs of short circuiting to voltage supply.
- After rectification: Check the sensor.
If the reading is below 5 Volts:
- Check the ECM connector.
Checking the ECM Connector
^ Switch Ignition OFF.
^ EGR temperature sensor disconnected.
^ Rectify the ECM connector with regard to contact resistance and oxidation.
^ ECM connected.
^ Switch Ignition ON.
^ Connect a voltmeter between EGR temperature sensor connector 1 (towards the ECM) and ground.
The voltmeter should show approx. 5 Volts.
It the reading is OK:
- The source of the DTC is poor contact in the ECM connector.
If the reading is incorrect:
- Check the lead between EGR temperature sensor connector 1 and ECM A35 for signs of a break.
Checking the EGR Temperature Sensor
^ Switch Ignition OFF.
^ EGR temperature sensor disconnected.
^ Connect an ohmmeter between connectors 1 and 2 on the EGR temperature sensor's connector (towards the temperature sensor).
The ohmmeter should show approx. 200K ohms at +20°C (68°F) (see diagram).
If the reading is OK:
- The cause of the DTC is poor contact in the EGR temperature sensor's connector.
- Rectify the connector with regard to contact resistance and oxidation.
If the reading is incorrect:
- Test with a new EGR temperature sensor.
Checking the Sensor
The EGR temperature sensor may break as a sequential fault resulting from short circuiting of the signal lead to voltage supply. Check the EGR temperature sensor as below.
^ Switch Ignition OFF.
^ EGR temperature sensor disconnected.
^ Connect an ohmmeter between connectors 1 and 2 on the EGR temperature sensor's connector (towards the temperature sensor).
The ohmmeter should show approx. 200K ohms at +2O°C (68°F) (see diagram).
If the reading is OK:
- EGR temperature sensor is OK.
If the reading is incorrect:
- Test with a new EGR temperature sensor.
SIGNAL TOO LOW
Checking the EGR Temperature Sensor Signal
^ START the engine and let it run at idling speed.
^ Look up the DTC parameter list.
^ Check the voltage at the EGR temperature sensor.
Voltage should be higher than 0.1 Volt.
If the reading is OK:
- The fault is intermittent.
- Proceed to: INTERMITTENT FAULT, SIGNAL TOO LOW section below.
If the reading differs:
- Check the signal lead.
Checking the Signal Lead
^ Switch Ignition OFF.
^ Disconnect the EGR temperature sensor.
^ START the engine and let it run at idling speed.
^ Look up the DTC parameter list.
^ Read off the EGR temperature sensor signal.
The reading should be about 5 Volts.
If the reading is OK:
- Check the EGR temperature sensor.
If the reading is incorrect:
- Check the lead between EGR temperature sensor connector 1 and ECM A35 for signs of short circuiting to ground.
Checking the EGR Temperature Sensor
^ Switch Ignition OFF.
^ EGR temperature sensor disconnected.
^ Connect an ohmmeter between connectors 1 and 2 on the EGR temperature sensor connector (towards temperature sensor).
The ohmmeter should show approx. 200K ohms at +20°C (68°F) (see diagram).
If the reading is OK:
- The cause of the DTC is poor contact in the EGR temperature sensor's connector.
- Rectify the connector with regard to contact resistance and oxidation.
If the reading is incorrect:
- Test with a new EGR temperature sensor.
FAULTY SIGNAL
Checking the Leads and Connections
^ Check the EGR temperature sensor's and the ECM's connectors for signs of loose connection as well as contact resistance and oxidation.
^ Check the lead between EGR temperature sensor connector 1 and ECM A35 for signs of an intermittent break, intermittent short circuiting to ground as well as intermittent short circuiting to voltage supply.
^ Check the lead between EGR temperature connector 2 and ECM A18 for signs of an intermittent break.
If no fault can be found:
- Test with a new EGR temperature sensor.
INTERMITTENT FAULT, SIGNAL TOO HIGH
Checking Leads and Connectors
^ Check the EGR temperature sensor's connector for signs of a loose connection and contact resistance and oxidation.
^ Check the lead between the EGR temperature sensor's connector 1 and control module A35 for signs of an intermittent break and for intermittent short circuiting to voltage supply.
^ Check the lead between the EGR temperature sensor's connector 2 and the control module A18 for signs of an intermittent break.
INTERMITTENT FAULT, SIGNAL TOO LOW
Checking Leads and Connectors
^ Check the lead between the EGR temperature sensor's connector 1 and control module A35 for signs of intermittent short circuiting to ground.