Code
P242C
Generic
P — Powertrain
Exhaust Gas Temperature Sensor Circuit Low Bank 1 Sensor 3
Views:
UK: 18
EN: 51
RU: 27
AI status
Completed
Completed
100%
Causes
- Failed or degraded EGT sensor (Bank 1 Sensor 3)
- Open circuit or broken wiring in sensor harness
- Short to ground in the sensor signal circuit
- Corroded or loose connector / poor pin contact
- Poor sensor ground or power supply problem
- ECM/PCM input fault or software issue
Symptoms
- Check Engine MIL illuminated (DTC stored)
- Possible engine derate or reduced performance in some vehicles
- Failed emissions or catalyst-related warnings
- Reduced ability to control regeneration on diesel DPF systems (if equipped)
- Inconsistent or implausible EGT readings in live data
What to check
- Read freeze frame and live data with a scan tool; confirm Bank 1 Sensor 3 EGT value is very low or frozen near a minimum value
- Compare Bank 1 Sensor 3 reading to other EGT sensors (Bank 1 Sensor 1/2 or Bank 2 sensors)
- Perform a visual inspection of sensor, connector, and wiring for damage, heat exposure, contamination, or corrosion
- Inspect pins for bent, pushed-out, or corroded terminals; check connector locking tab
- Check fuses and related power/ground circuits if sensor uses a supplied reference
- Backprobe connector and measure signal voltage or millivolt output with key ON and during engine conditions per vehicle service manual
Signal parameters
- General: sensor signal expected to change with temperature – manufacturer designs differ (thermistor or thermocouple)
- Typical signal interface examples: 0–5.0 V reference or a low-voltage thermocouple/millivolt signal; a persistently low voltage/mV indicates a low circuit
- Low-circuit trigger: signal at or near 0 V (or near 0 mV for thermocouples) or well below expected live-data values for operating conditions
- Expected behavior: signal should rise as exhaust temperature increases; compare to other sensors on same engine
Diagnostic algorithm
- Connect a diagnostic scan tool; record freeze frame, DTC status (pending/confirmed) and live EGT sensor values.
- Visually inspect Bank 1 Sensor 3, its connector and harness routing for heat damage, chafing, corrosion, soot, or contamination. Repair obvious damage.
- With ignition OFF, disconnect sensor connector and inspect pins for corrosion/loose contacts; reconnect securely.
- With connector connected, backprobe the signal, ground and reference (if present) pins. With key ON and engine cold, note resting voltage, then start engine and observe change. Compare to service specifications or other EGT sensors.
- If sensor uses a thermistor: measure sensor resistance vs temperature (remove sensor if necessary) and compare to spec. If thermocouple: measure millivolt output while heating sensor (use caution) or compare live mV to expected.
- Perform continuity test on wiring between sensor connector and ECM pin; check for short to ground or short to battery. Wiggle harness while observing live-data for intermittent faults.
- If wiring and connector are good, substitute a known-good sensor (if available) or install a new sensor and retest.
- If replacement sensor does not clear the fault, check ECM power/ground and input circuitry; consult manufacturer technical information for ECM-level diagnostics and reprogramming.
- After repairs, clear codes and perform a road/operational test to confirm the code does not recur. If intermittent, monitor with scan tool during varied engine/exhaust temps.
Likely causes
- Failed EGT sensor element or connector corrosion
- Wiring shorted to chassis ground near the sensor (common for low-signal DTC)
- Broken/chafed harness insulation at a high-heat area
- Poor ground at sensor or ECM pin
- Loose connector not making contact
Fault status
Status
Stored when the engine control module detects the Bank 1 Sensor 3 exhaust gas temperature sensor circuit is producing a persistently low signal (below expected range), indicating a possible short to ground, open/failed sensor, or wiring/connector fault.
Repair difficulty: Medium
Diagnostic time: 1.0-2.5 hours
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Code
P242C
LAND ROVER
P — Powertrain
Exhaust gas temperature sensor - low circuit (bank 1, sensor 3)
Views:
UK: 3
EN: 19
RU: 4
AI status
Completed
Completed
100%
Causes
- Failed or degraded EGT sensor (Bank 1 Sensor 3)
- Open circuit or broken wiring in sensor harness
- Short to ground in the sensor signal circuit
- Corroded or loose connector / poor pin contact
- Poor sensor ground or power supply problem
- ECM/PCM input fault or software issue
Symptoms
- Check Engine MIL illuminated (DTC stored)
- Possible engine derate or reduced performance in some vehicles
- Failed emissions or catalyst-related warnings
- Reduced ability to control regeneration on diesel DPF systems (if equipped)
- Inconsistent or implausible EGT readings in live data
What to check
- Read freeze frame and live data with a scan tool; confirm Bank 1 Sensor 3 EGT value is very low or frozen near a minimum value
- Compare Bank 1 Sensor 3 reading to other EGT sensors (Bank 1 Sensor 1/2 or Bank 2 sensors)
- Perform a visual inspection of sensor, connector, and wiring for damage, heat exposure, contamination, or corrosion
- Inspect pins for bent, pushed-out, or corroded terminals; check connector locking tab
- Check fuses and related power/ground circuits if sensor uses a supplied reference
- Backprobe connector and measure signal voltage or millivolt output with key ON and during engine conditions per vehicle service manual
Signal parameters
- General: sensor signal expected to change with temperature – manufacturer designs differ (thermistor or thermocouple)
- Typical signal interface examples: 0–5.0 V reference or a low-voltage thermocouple/millivolt signal; a persistently low voltage/mV indicates a low circuit
- Low-circuit trigger: signal at or near 0 V (or near 0 mV for thermocouples) or well below expected live-data values for operating conditions
- Expected behavior: signal should rise as exhaust temperature increases; compare to other sensors on same engine
Diagnostic algorithm
- Connect a diagnostic scan tool; record freeze frame, DTC status (pending/confirmed) and live EGT sensor values.
- Visually inspect Bank 1 Sensor 3, its connector and harness routing for heat damage, chafing, corrosion, soot, or contamination. Repair obvious damage.
- With ignition OFF, disconnect sensor connector and inspect pins for corrosion/loose contacts; reconnect securely.
- With connector connected, backprobe the signal, ground and reference (if present) pins. With key ON and engine cold, note resting voltage, then start engine and observe change. Compare to service specifications or other EGT sensors.
- If sensor uses a thermistor: measure sensor resistance vs temperature (remove sensor if necessary) and compare to spec. If thermocouple: measure millivolt output while heating sensor (use caution) or compare live mV to expected.
- Perform continuity test on wiring between sensor connector and ECM pin; check for short to ground or short to battery. Wiggle harness while observing live-data for intermittent faults.
- If wiring and connector are good, substitute a known-good sensor (if available) or install a new sensor and retest.
- If replacement sensor does not clear the fault, check ECM power/ground and input circuitry; consult manufacturer technical information for ECM-level diagnostics and reprogramming.
- After repairs, clear codes and perform a road/operational test to confirm the code does not recur. If intermittent, monitor with scan tool during varied engine/exhaust temps.
Likely causes
- Failed EGT sensor element or connector corrosion
- Wiring shorted to chassis ground near the sensor (common for low-signal DTC)
- Broken/chafed harness insulation at a high-heat area
- Poor ground at sensor or ECM pin
- Loose connector not making contact
Fault status
Status
Stored when the engine control module detects the Bank 1 Sensor 3 exhaust gas temperature sensor circuit is producing a persistently low signal (below expected range), indicating a possible short to ground, open/failed sensor, or wiring/connector fault.
Repair difficulty: Medium
Diagnostic time: 1.0-2.5 hours
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Land Rover Range Rover — Electrical Library (LRL 0453ENG, 2002)
Workshop Manual199,00 UAH
Your experience will help others
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Was this AI description helpful?
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