Diagnosis and check 2.7L (Discovery 3)

Inspection and verification

1. Make sure the customer's complaint is valid.

2. Visually inspect for obvious mechanical and electrical problems.

Mechanical factors	Electrical Factors
Leaks metal fatigue Pipes catalytic converter Muffler (And) Connections supports Gap around elements	Fuses Wiring harness electrical connector (s) Sensor (And) Engine control module (ECM)

3. If an obvious cause of a problem you identified or described by a customer is found, resolve it before proceeding to the next steps (if possible).

4. Use an approved diagnostic system or scan tool (tester), to retrieve all DTCs before referring to the symptom table or DTC index (DTC).

Clear all DTCs after troubleshooting.

Symptom table

Symptom	Possible reasons	Action
Noise or leaks in the exhaust system	Exhaust system / system elements	Install new elements if necessary. Refer to the relevant section in the workshop manual.
Insufficient power	Air intake system malfunction Clogged exhaust system Low fuel pressure	Check the air intake system. Check muffler or catalytic converter for blockage, install new as required. Check the pressure in the fuel system. Refer to the relevant section in the workshop manual.

DTC index

NOTE: Universal Scan Tools cannot read the listed codes or can only read 5-digit codes. Match the 5 digits from the scan tool with the first 5 digits of the listed 7 digit code to identify the problem (the last 2 digits give additional information read by the diagnostic system approved by the manufacturer).

NOTE: See Section 303-14 for a complete list of ECM DTCs "Electronic engine management system" in the workshop manual.

DTCs	Description	Possible reasons	Action
P042562	Catalytic Converter Temperature Sensor Circuit (bank 1, sensor circuit 1)	Error when comparing the signal from the temperature sensor before the catalytic converter (right bank of cylinders, sensor 1) Comparison of pre-catalyst temperature sensor correlation with at least two other sensors Malfunction of the temperature sensor in front of the catalytic converter Pre-catalyst temperature sensor signal circuit - short to ground, short to battery, or open circuit	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to electrical circuit diagrams and check pre-catalyst temperature sensor circuit for short to ground or short to battery, open circuit. Check the temperature sensor upstream of the catalytic converter for dirt, corrosion, water damage. Replace temperature sensor upstream of catalytic converter.
P042600	Catalytic Converter Temperature Sensor Circuit Operating Range/Performance Problems (bank 1, sensor circuit 1)	Error when checking the signal gradient from the temperature sensor before the catalytic converter (right bank of cylinders, sensor 1) Malfunction of the temperature sensor in front of the catalytic converter Pre-catalyst temperature sensor signal circuit - short to ground, short to battery, or open circuit Pre-catalytic converter temperature sensor high circuit resistance	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to electrical circuit diagrams and check pre-catalyst temperature sensor circuit for short to ground or battery, open circuit Poor contact. Install a new sensor if necessary.
P04261A	Catalytic Converter Temperature Sensor Circuit Operating Range/Performance Problems (bank 1, sensor circuit 1)	Pre-catalyst temperature sensor circuit resistance below threshold (right bank of cylinders, sensor 1) Plausibility of temperature sensor signal before catalytic converter at cold start, temperature difference too high Temperature sensor in front of the catalytic converter: fixation at a high temperature value	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to the electrical circuit diagrams and check the pre-catalyst temperature sensor circuit for low resistance, short to ground Replace the pre-catalyst temperature sensor.
P04261B	Catalytic Converter Temperature Sensor Circuit Operating Range/Performance Problems (bank 1, sensor circuit 1)	Pre-catalyst temperature sensor circuit resistance above threshold (right bank of cylinders, sensor 1) Plausibility of pre-catalyst temperature sensor signal at cold start, temperature difference too low Temperature sensor in front of the catalytic converter: fixation at a high temperature value	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to the electrical circuit diagrams and check the pre-catalyst temperature sensor circuit for high resistance, open circuit Replace the pre-catalyst temperature sensor.
P04261E	Catalytic Converter Temperature Sensor Circuit Operating Range/Performance Problems (bank 1, sensor circuit 1)	Pre-catalyst temperature sensor circuit resistance out of range (right bank of cylinders, sensor 1) Plausibility of temperature sensor signal before catalytic converter with engine running, temperature too low Temperature sensor in front of the catalytic converter: fixing at a low temperature value	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to electrical circuit diagrams and check pre-catalyst temperature sensor circuit for short to ground or battery, open circuit Check pre-catalyst temperature sensor for dirt, corrosion, water damage. Replace temperature sensor upstream of catalytic converter.
P042700	Catalytic converter temperature sensor circuit - low voltage (bank 1, sensor circuit 1)	Pre-catalyst temperature sensor signal below minimum voltage threshold (right bank of cylinders, sensor 1) Malfunction of the temperature sensor in front of the catalytic converter Pre-catalyst temperature sensor circuit - short to ground	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to the electrical circuit diagrams and check the pre-catalyst temperature sensor circuit for a short to ground Install a new sensor if necessary.
P042800	Catalytic converter temperature sensor circuit high voltage (bank 1, sensor circuit 1)	Pre-catalyst temperature sensor signal above maximum voltage threshold (right bank of cylinders, sensor 1) Malfunction of the temperature sensor in front of the catalytic converter Pre-catalytic converter temperature sensor circuit - short circuit to battery, open circuit	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to electrical circuit diagrams and check pre-catalyst temperature sensor circuit for short to battery, open circuit Install a new sensor if necessary.
P042A62	Catalytic Converter Temperature Sensor Circuit (bank 1, sensor circuit 2)	Error when comparing the signal from the temperature sensor after the catalytic converter (right bank of cylinders, sensor 2) Comparison of post-catalyst temperature sensor correlation with at least two other sensors Malfunction of the temperature sensor after the catalytic converter Post catalytic converter temperature sensor signal circuit - short to ground, short to battery, or open circuit	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to electrical circuit diagrams and check post catalytic converter temperature sensor circuit for short to ground or short to battery, open circuit. Check the temperature sensor after the catalytic converter for dirt, corrosion, water damage. Replace temperature sensor after catalytic converter.
P042B00	Catalytic Converter Temperature Sensor Circuit Operating Range/Performance Problems (bank 1, sensor circuit 1)	Error when checking the signal gradient from the temperature sensor after the catalytic converter (right bank of cylinders, sensor 2) Malfunction of the temperature sensor after the catalytic converter Post catalytic converter temperature sensor signal circuit - short to ground, short to battery, or open circuit Post catalytic converter temperature sensor high circuit resistance	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to electrical circuit diagrams and check post catalytic converter temperature sensor circuit for short to ground or battery, open circuit Poor contact. Install a new sensor if necessary.
P042B1A	Catalytic Converter Temperature Sensor Circuit Operating Range/Performance Problems (bank 1, sensor circuit 1)	Post-catalyst temperature sensor circuit resistance below threshold (right bank of cylinders, sensor 2) Plausibility of post-catalyst temperature sensor signal at cold start, temperature difference too high Temperature sensor after catalytic converter: fixation at a high temperature value	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to the electrical circuit diagrams and check the post-catalyst temperature sensor circuit for low resistance, short to ground Replace the post-catalyst temperature sensor.
P042B1B	Catalytic Converter Temperature Sensor Circuit Operating Range/Performance Problems (bank 1, sensor circuit 1)	Post-catalyst temperature sensor circuit resistance above threshold (right bank of cylinders, sensor 2) Plausibility of post-catalyst temperature sensor signal at cold start, temperature difference too low Temperature sensor after catalytic converter: fixation at a high temperature value	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to the electrical circuit diagrams and check the post-catalyst temperature sensor circuit for high resistance, open circuit Replace the post-catalyst temperature sensor.
P042B1E	Catalytic Converter Temperature Sensor Circuit Operating Range/Performance Problems (bank 1, sensor circuit 1)	Post-catalyst temperature sensor circuit resistance out of range (right bank of cylinders, sensor 2) Plausibility of post-catalytic converter temperature sensor signal with engine running, temperature too low Temperature sensor after catalytic converter: fixing at a low temperature value	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to electrical circuit diagrams and check post catalytic converter temperature sensor circuit for short to ground or short to battery, open circuit. Check the temperature sensor after the catalytic converter for dirt, corrosion, water damage. Replace temperature sensor after catalytic converter.
P042C00	Catalytic converter temperature sensor circuit - low voltage (bank 1, sensor circuit 2)	Post-catalyst temperature sensor signal below minimum voltage threshold (right bank of cylinders, sensor 2) Malfunction of the temperature sensor after the catalytic converter Post-catalyst temperature sensor circuit - short to ground	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to the electrical circuit diagrams and check the post-catalyst temperature sensor circuit for a short to ground Install a new sensor if necessary.
P042D00	Catalytic converter temperature sensor circuit high voltage (bank 1, sensor circuit 2)	Post-catalyst temperature sensor signal above maximum voltage threshold (right bank of cylinders, sensor 2) Malfunction of the temperature sensor after the catalytic converter Post catalytic converter temperature sensor circuit - short to battery, open circuit	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to electrical circuit diagrams and check post catalytic converter temperature sensor circuit for short to battery, open circuit Install a new sensor if necessary.
P242A62	Exhaust Gas Temperature Sensor Circuit - Bank 1 Sensor 3	Error when comparing signal from temperature sensor after DPF (right bank of cylinders, sensor 3) Comparison of post-DPF temperature sensor correlation with at least two other sensors Temperature sensor malfunction after DPF	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to electrical circuit diagrams and check downstream DPF temperature sensor circuit for short to ground or short to battery, open circuit Check downstream DPF temperature sensor for dirt, corrosion, water damage. Replace temperature sensor after DPF.
P242B1A	Exhaust Gas Temperature Sensor Circuit Range/Performance Problems - Bank 1 Sensor 3	Post DPF Temperature Sensor Circuit Resistance Below Threshold (right bank of cylinders, sensor 3) Plausibility of temperature sensor signal after DPF at cold start, temperature difference too high Temperature sensor malfunction after DPF Temperature sensor after DPF: fixing at a high temperature value	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to the electrical circuit diagrams and check the downstream DPF temperature sensor circuit for low resistance, short to ground Replace the downstream DPF temperature sensor.
P242B1B	Exhaust Gas Temperature Sensor Circuit Range/Performance Problems - Bank 1 Sensor 3	Post-DPF Temperature Sensor Circuit Resistance Above Threshold (right bank of cylinders, sensor 3) Plausibility of temperature sensor signal after DPF at cold start, temperature difference too low Temperature sensor malfunction after DPF Temperature sensor after DPF: fixing at a high temperature value	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to the electrical circuit diagrams and check the post-DPF temperature sensor circuit for high resistance, open circuit Replace the post-DPF temperature sensor.
P242B1E	Exhaust Gas Temperature Sensor Circuit Range/Performance Problems - Bank 1 Sensor 3	Post DPF temperature sensor circuit resistance out of range (right bank of cylinders, sensor 3) Plausibility of temperature sensor signal after DPF with engine running, temperature too low Temperature sensor malfunction after DPF Temperature sensor after DPF: fixing at a low temperature value	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to electrical circuit diagrams and check downstream DPF temperature sensor circuit for short to ground or short to battery, open circuit Check downstream DPF temperature sensor for dirt, corrosion, water damage. Replace temperature sensor after DPF.
P242C00	Exhaust Gas Temperature Sensor Circuit Low - Bank 1 Sensor 3	Temperature sensor signal after DPF below minimum voltage threshold (right bank of cylinders, sensor 3) Temperature sensor malfunction after DPF Post DPF temperature sensor circuit - short to ground, high resistance	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to the electrical circuit diagrams and check the post-DPF temperature sensor circuit for high resistance, short to ground Install a new sensor if necessary.
P242D00	Exhaust Gas Temperature Sensor Circuit High - Bank 1 Sensor 3	Temperature sensor signal after DPF is above the maximum voltage threshold (right bank of cylinders, sensor 3) Temperature sensor malfunction after DPF Temperature sensor circuit after DPF - short circuit to + battery, open circuit	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to electrical circuit diagrams and check post-DPF temperature sensor circuit for short to battery, open circuit Install a new sensor if necessary.
P242E00	Intermittent malfunction / chaotic signal in the electrical circuit of the exhaust gas temperature sensor - bank 1, sensor 3	Error when checking the signal gradient from the temperature sensor after DPF (right bank of cylinders, sensor 3) Temperature sensor malfunction after DPF Post DPF temperature sensor signal circuit - short to ground, short to battery, or open circuit	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to electrical circuit diagrams and check post-DPF temperature sensor circuit for short to ground or battery, open circuit Poor contact. Install a new sensor if necessary.
P242F68	Clogging of the filter of products of combustion of diesel fuel - accumulation of soot	DPF Event Information DPF filter partially clogged DPF circuit internal short to ECM	The DPF filter needs to be regenerated. Please refer to the instruction manual.
P244A00	Too low pressure drop across the diesel flue filter (row 1)	Too low differential pressure on the filter of products of combustion of diesel fuel - the right number of cylinders	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to electrical circuit diagrams and check DPS circuit for short to ground or short to battery, open circuit Check DPS system external piping for leaks and damage. Check the internal DPF filter element for damage. Install the DPF in accordance with regulations
P244B00	Too high differential pressure on the filter of combustion products of diesel fuel (row 1)	Too high differential pressure on the filter of products of combustion of diesel fuel - the right number of cylinders Diesel Combustion Filter - Internal Failure	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Contact your dealer's technical support.
P245300	Diesel Flue Filter Pressure Sensor A Circuit Range/Performance Problems	DPS jam DPS - short circuit to ground, short circuit to battery + or open circuit Plausibility of the signal of the differential pressure sensor on the filter of combustion products of diesel fuel before starting DPS system dirty or clogged	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to electrical circuit diagrams and check DPS circuit for short to ground or short to battery, open circuit Check DPS system for contamination or obstruction. Check for DPS sticking. Install the sensor in accordance with the regulations
P245329	Diesel Flue Filter Pressure Sensor A Circuit Range/Performance Problems	DPS signal abnormal Checking the plausibility of the signal of the differential pressure sensor on the filter of combustion products of diesel fuel during engine operation DPS system dirty or clogged DPS jam DPS - short circuit to ground, short circuit to battery + or open circuit	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to electrical circuit diagrams and check DPS circuit for short to ground or short to battery, open circuit Check DPS system for contamination or obstruction. Check the external piping of the DPS system for leaks and damage. Check for DPS sticking. Install the sensor in accordance with the regulations
P245400	Diesel Combustion Filter Pressure Sensor A Circuit Low	DPS signal below minimum threshold DPS failure DPS circuit - short to ground, high resistance	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to electrical circuit diagrams and check DPS circuit for short to ground and high resistance. Install the sensor in accordance with the regulations
P245500	Diesel Combustion Filter Pressure Sensor A High Voltage	DPS signal above maximum threshold DPS failure DPS circuit - short circuit to battery, open circuit	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to electrical circuit diagrams and check DPS circuit for short to battery, open circuit Install sensor properly
P245600	Intermittent malfunction/interruptions in the electrical circuit of the diesel combustion filter pressure sensor A	DPS gradient improbability DPS failure DPS circuit short to ground, short to battery, or open circuit	Perform the pinpoint test associated with this DTC using the manufacturer's approved diagnostic system. Refer to electrical circuit diagrams and check DPS circuit for short to ground or short to battery, open circuit Install sensor properly
P245800	Duration of regeneration of the filter of products of combustion of diesel fuel	Regeneration delay timer setting out of range DPF circuit internal short to ECM	Contact your dealer's technical support.