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Home >> Volvo >> 1995 >> 960 L6-3.0L VIN 95 B6304F >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> Manufacturer Code Charts >> EFI / DTC Codes (Engine Control System) >> DTC 4-1-3

DTC 4-1-3

4-1-3 EGR TEMPERATURE SENSOR SIGNAL




Trouble Code Conditions
Positive Temperature Co-efficient (PTC) sensor:
If voltage across EGR temperature sensor exceeds 3.6 volts with engine cold (high signal), is less than 1.4 volts with engine warm (low signal), or varies markedly (faulty signal), the Engine Control Module (ECM) notes it as a fault, and Diagnostic Trouble Code (DTC) 4-1-3 is set.

Negative Temperature Co-efficient (NTC) sensor:
If voltage across EGR temperature sensor exceeds 4.4 volts with engine warm (high signal), is less than 0.5 volts with engine cold (low signal), or varies markedly (faulty signal), the Engine Control Module (ECM) notes it as a fault, and Diagnostic Trouble Code (DTC) 4-1-3 is set.

Substitute value(s)
- Heated Oxygen Sensor (HO2S) inhibited.
- Idle Air Control (IAC) valve adaption inhibited.

Fault source(s)
Signal too high:
- Signal lead short circuited to live.
- Break in signal lead.
- Break in ground lead.
- Contact resistance in connectors.
- Defective EGR temperature sensor.

Signal too low:
- Signal lead short circuited to ground.
- Defective EGR temperature sensor.

Faulty signal:
- Signal lead short circuited to ground.
- Break in signal lead.
- Break in ground lead.
- Contact resistance in connectors.
- Defective EGR temperature sensor.

Fault symptom(s)
- None.

TEST PROCEDURE




OTHER DTC'S
- Read off other DTCs.

If DTC 1-5-4 is stored:
^ Fault trace DTC 1-5-4, EGR system.

If DTCs 1-2-3, 4-1-1 (2-4-3), 1-4-3, 4-3-3 and/or 3-1-4 are stored:
^ Check EGR temperature sensor, Engine Coolant Temperature(ECT) sensor, Throttle Position (TP) sensor, Knock Sensor (KS) and Camshaft Position (CMP) sensor common connector # 30 on ECM for contact resistance and oxidation, as well as break.

If none of above DTCs are stored:
^ Status report. Proceed to STATUS REPORT section below.




STATUS REPORT
^ Signal too high.
- Proceed to SIGNAL TOO HIGH section below.

^ Signal too low.
- Proceed to SIGNAL TOO LOW section below.

^ Faulty signal.
- Proceed to FAULTY SIGNAL section below.




SIGNAL TOO HIGH
Check EGR temperature sensor voltage
- Start and warm up engine.
- Enter DTC parameter list. When engine temperature exceeds 60°C (140°F), switch off engine and restart.
- Read off value of EGR temperature.

Value should be as follows:

EGR temperature sensor with PTC resistance:
^ Value should read between 1.8 - 2.2 volts depending on sensor temperature (1.8 at 0°C (32°F) and 2.2 at 80°C (176°F)). Note that voltage rises with temperature.

EGR temperature sensor with NTC resistance:
^ Value should read between 4.6 - 1.8 volts depending on sensor temperature (4.6 at 0°C (32°F) and 1.8 at 80°C (176°F)). Note that resistance falls with rising temperature.

If value OK:
^ Intermittent fault, signal too high. Proceed to INTERMITTENT FAULT, SIGNAL TOO HIGH section below.

If value 5 volts:
^ Check ground lead resistance to ground. Proceed to CHECK GROUND LEAD RESISTANCE TO GROUND section below.

CHECK GROUND LEAD RESISTANCE TO GROUND
- Ignition off.
- EGR temperature sensor disconnected.



- Connect an ohmmeter between EGR temperature sensor connector contact 2 (to ECM) and ground.

Ohmmeter should read approx. 0 ohms.

If value OK:
^ Check signal lead. Proceed to CHECK SIGNAL LEAD section below.

If value differs:
^ Check connector. Proceed to CHECK CONNECTOR section below.




CHECK CONNECTOR
- Ignition off.
- EGR temperature sensor disconnected.
- Ignition off.
- EGR temperature sensor disconnected.
- Check ECM connector and 55-pin connector in central relay unit (A3/D) connector 12 for contact resistance and oxidation.
- ECM connected.



- Connect an ohmmeter between EGR temperature sensor connector contact 2 (to ECM) and ground.

Ohmmeter should read approx. 0 ohms.

If value OK:
^ Source of DTC is bad contact in ECM connector.

If value differs:
^ Check lead between EGR temperature sensor connector 2 and ECM # 30 for break.

CHECK SIGNAL LEAD
- Ignition on.
- EGR temperature sensor disconnected.



- Connect a voltmeter between EGR temperature sensor connector contact 1 (to ECM) and ground.

Voltmeter should read approx. 5 volts.

If value OK:
^ Test with a new EGR temperature sensor.

If voltmeter reads over 5 volts:
^ Check lead between EGR temperature sensor connector 1 and ECM # 46 for short circuit to live.
^ After fixing, check sensor. Proceed to CHECK SENSOR section below.

If voltmeter reads under 5 volts:
^ Check connector. Proceed to CHECK CONNECTOR section below.

CHECK CONNECTOR
- Ignition off.
- EGR temperature sensor disconnected.
- Check ECM connector and 55-pin connector in central relay unit (A31D) connector 8 for contact resistance and oxidation.
- ECM connected.
- Ignition on.
- Connect a voltmeter between EGR temperature sensor connector contact 1 (to ECM) and ground.

Voltmeter should read approx. 5 volts.

If value OK:
^ Source of DTC is bad contact in ECM connector.

If value differs:
^ Check lead between EGR temperature sensor connector 1 and ECM # 46 for break.

CHECK SENSOR
The EGR temperature sensor can break down as a sequential fault if a signal lead is short circuited to live.
Check EGR temperature sensor as below.

- Ignition off.
- EGR temperature sensor disconnected.
- Connect an ohmmeter between connector 1 and 2 on EGR temperature sensor connector (to temperature sensor).

Ohmmeter should read approx 200 k ohms if sensor temperature is +20°C (68°F).

If value OK:
^ EGR temperature sensor is OK.

If value differs:
^ Test with a new EGR temperature sensor.




SIGNAL TOO LOW
Check EGR temperature sensor voltage
- Start and warm up engine.
- Enter DTC parameter list. When engine temperature exceeds 60°C (140°F) switch off engine and restart.
- Read off value of EGR temperature.

Value should be as follows:

EGR temperature sensor with PTC resistance:
^ Value should read between 1.8 - 2.2 volts depending on sensor temperature (1.8 at 0°C (32°F) and 2.2 at 80°C (176°F)). Note that voltage rises with temperature.

EGR temperature sensor with NTC resistance:
^ Value should read between 4.6 - 1.8 volts depending on sensor temperature (4.6 at 0°C (32°F) and 1.8 at 80°C (176°F)). Note that voltage decreases with rising temperature.

If value OK
^ Intermittent fault, signal too low. Proceed to INTERMITTENT FAULT, SIGNAL TOO LOW section below.

If value is 0 volts:
^ Check signal lead. Proceed to CHECK SIGNAL LEAD section below.




CHECK SIGNAL LEAD
- Ignition off.
- Disconnect EGR temperature sensor.
- Start engine and allow to idle.
- Enter DTC parameter list.
- Read off EGR temperature sensor signal.

Value should read approx. 5 volts.

If value OK:
^ Test with a new EGR temperature sensor.

If value differs:
^ Check lead between EGR temperature sensor connector contact 1 and ECM # 46 for short circuit to ground.




FAULTY SIGNAL
Check EGR temperature sensor voltage
- Start and warm up engine.
- Enter DTC parameter list. When engine temperature exceeds 60°C (140°F), switch off engine and restart.
- Read off value of EGR temperature.

Value should read as follows:

EGR temperature sensor with PTC resistance:
^ Value should read between 1.8 - 2.2 volts depending on sensor temperature (1.8 at 0°C (32°F) and 2.2 at 80°C (176°F)). Note that voltage rises with temperature.

EGR temperature sensor with NTC resistance:
^ Value should read between 4.6 - 1.8 volts depending on sensor temperature (4.6 at 0°C (32°F) and 1.8 at 80°C (176°F)). Note that voltage decreases with rising temperature.

If value OK:
^ Intermittent fault, faulty signal. Proceed to INTERMITTENT FAULT, FAULTY SIGNAL section below.

If value is 5 volts:
^ Check ground lead resistance to ground. Proceed to CHECK GROUND LEAD RESISTANCE TO GROUND section above.

If value is 0 volts:
^ Check signal lead. Proceed to CHECK SIGNAL LEAD section below.




INTERMITTENT FAULT, SIGNAL TOO HIGH
Check leads and connectors
- Check EGR temperature sensor connector for bad contact, as well as contact resistance and oxidation.
- Check lead between EGR temperature sensor connector 1 and ECM # 46 for intermittent break, as well as intermittent short circuit to live.
- Check lead between EGR temperature sensor connector 2 and ECM # 30 for intermittent break.

INTERMITTENT FAULT, SIGNAL TOO LOW
Check leads and connectors
- Check lead between EGR temperature sensor connector 2 and ECM # 30 for intermittent short circuit to ground.

INTERMITTENT FAULT, FAULTY SIGNAL
Check leads and connectors
- Check EGR temperature sensor and ECM connector for bad contact, as well as contact resistance and oxidation.
- Check lead between EGR temperature sensor connector 1 and ECM # 46 for intermittent break, intermittent short circuit to ground, as well as intermittent short circuit to live.
- Check lead between EGR temperature sensor connector 2 and ECM # 30 for intermittent break.
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