P2395 – Cylinder 4 Exhaust Gas Temperature Sensor Circuit

System: Powertrain | Standard: ISO/SAE Controlled | Fault type: Circuit | Location: Cylinder 4

Definition source: SAE J2012/J2012DA (industry standard)

DTC P2395 indicates the powertrain control module has detected an electrical circuit-related issue associated with the Cylinder 4 exhaust gas temperature (EGT) sensor circuit. This code describes a circuit fault, not a confirmed failed sensor or a confirmed exhaust temperature problem. Symptoms and test results can vary by vehicle because sensor type, wiring routing, and control strategies differ by platform. Use the vehicle’s service information to confirm component location (Cylinder 4 identification varies), connector pinouts, and the exact enabling conditions used to set the code.

What Does P2395 Mean?

P2395 – Cylinder 4 Exhaust Gas Temperature Sensor Circuit means the control module has identified a fault in the electrical circuit for the exhaust gas temperature sensor associated with Cylinder 4. Per SAE J2012 naming conventions, this DTC is reporting a circuit-type problem (such as an open, short, poor connection, or power/ground issue) in the signal path the module uses to read that EGT sensor. The code itself does not specify whether the circuit is high, low, open, or intermittent; pinpoint testing is required to determine the exact circuit failure mode and its root cause.

Quick Reference

• System: Powertrain
• Official meaning: Cylinder 4 Exhaust Gas Temperature Sensor Circuit
• Standard: ISO/SAE controlled
• Fault type: Circuit
• Severity: MIL illumination is possible; engine protection strategies such as reduced power or altered fueling/aftertreatment control may occur depending on vehicle logic.

Symptoms

• MIL/Check Engine: Warning lamp illuminated with P2395 stored (current or pending).
• Reduced power: Engine torque may be limited if the control module can’t trust exhaust temperature feedback.
• Aftertreatment concerns: Regeneration/thermal management may be delayed, disabled, or run more often than expected (varies by vehicle).
• Driveability changes: Hesitation or altered throttle response may occur under load when temperature-based strategies are used.
• Fuel economy: Consumption may increase if fallback values are substituted for the missing/unreliable sensor input.
• Failed emissions test: Readiness monitors may not set or emissions-related functions may be impaired.
• Intermittent behavior: Symptoms may come and go with vibration, heat, or harness movement if the fault is connection-related.

Common Causes

• Harness damage: Chafed, melted, pinched, or stretched wiring to the cylinder 4 exhaust gas temperature (EGT) sensor, often near hot exhaust components.
• Connector problems: Loose fit, corrosion, moisture intrusion, terminal push-out, or damaged locking tabs at the sensor connector or engine harness connector.
• Open circuit: Broken conductor inside the insulation, cracked solder splice, or an internal open in the sensor element causing loss of signal continuity.
• Short circuit: Signal or supply/reference wire shorted to ground or to another circuit due to insulation damage or harness contact with metal edges.
• Power/ground issue: Missing sensor feed, poor ground, or excessive resistance in ground path (design varies by vehicle) affecting sensor operation and circuit integrity.
• High resistance: Partially damaged wiring, corroded terminals, or poor pin tension creating an intermittent or biased signal without a complete open.
• Sensor fault: Cylinder 4 EGT sensor internal electrical failure (open/short/unstable) verified by circuit and component testing.
• Control module/driver concern: Rare fault in the monitoring circuit within the control module or its connector pins after all wiring and sensor checks pass.

Diagnosis Steps

Tools typically needed include a scan tool with live-data and freeze-frame access, a digital multimeter, and vehicle-specific wiring diagrams/service information. Helpful additions are back-probing leads, a test light where appropriate, and basic hand tools to access connectors. If available, use a data-logging feature to capture intermittent events and a smoke-safe light/inspection mirror to examine routing near hot components.

1. Confirm the DTC and capture data: Scan for P2395 and all other codes. Save freeze-frame and note when the fault sets (startup, idle, load, regeneration events where applicable). Clear codes only after recording data.
2. Check for related faults: Look for other exhaust temperature, exhaust aftertreatment, or sensor circuit DTCs that may indicate a shared power/ground, shared connector, or harness section issue. Address power supply or shared circuit codes first if present.
3. Perform a visual inspection (cold): With the engine off and cool, inspect the cylinder 4 EGT sensor harness routing. Look for melted loom, contact with exhaust parts, abrasion points, missing clips, or evidence of recent repairs that could stress the wiring.
4. Inspect connectors and terminals: Disconnect the EGT sensor connector and check for corrosion, moisture, bent pins, spread terminals, poor pin retention, or terminal push-out. Verify the connector locks fully engage when reconnected.
5. Wiggle test while monitoring live data: Reconnect as needed and use scan tool live data for the EGT sensor signal/PID (naming varies by vehicle). Gently wiggle the harness and connector. Any sudden jumps, dropouts, or implausible changes suggest an intermittent connection or conductor break.
6. Verify circuit power/ground integrity: Using wiring diagrams, identify the circuit type (varies by vehicle). Key on as specified by service information and check for the presence of the correct feed/reference and a stable ground. If a ground is used, perform a voltage-drop test on the ground path under load to find excessive resistance.
7. Check for opens with continuity testing: With the circuit powered down per service information, test continuity from the sensor connector to the control module connector for each relevant wire. Flex the harness during testing to reveal intermittent opens. Repair any open or high-resistance segment found.
8. Check for shorts to ground/power/other circuits: Still powered down as required, test each circuit for unwanted continuity to ground and to adjacent circuits. Pay special attention to sections near exhaust heat shielding and brackets where insulation damage is common.
9. Sensor evaluation (electrical): If wiring and connectors test good, evaluate the cylinder 4 EGT sensor per service information. Depending on design, this may include resistance checks or verifying response behavior using live data as the exhaust warms. Replace the sensor only if it fails the specified tests.
10. Control module connector and pin fit check: If the sensor and wiring check out, inspect the control module connector for pin fit, corrosion, water intrusion, or backed-out terminals. Ensure proper connector seating and locking.
11. Validate the repair: Clear codes and perform a road test while logging live data. Recreate the conditions from freeze-frame when possible. Confirm P2395 does not return and that the EGT signal is stable without dropouts during vibration and load changes.

Professional tip: If P2395 is intermittent, prioritize fault replication and data capture: log the EGT PID(s) plus battery voltage and any related exhaust/aftertreatment temperature PIDs during a controlled wiggle test and a drive cycle. Intermittent opens or high resistance often appear only when the harness is heat-soaked or vibrating, so recheck routing near hot components and perform voltage-drop testing rather than relying on static continuity alone.

Possible Fixes & Repair Costs

Repair costs for P2395 vary widely by vehicle and depend on what testing confirms, access to the sensor and harness, and whether wiring repair or component replacement is required. Diagnose first to avoid replacing parts that are not responsible for the circuit fault.

• Repair wiring faults: Fix open circuits, chafed insulation, melted sections near hot components, or pinched harness routing affecting the cylinder 4 exhaust gas temperature sensor circuit.
• Connector service: Clean corrosion, remove moisture intrusion, correct poor terminal tension, and repair bent, spread, or backed-out pins at the sensor connector and control module connector.
• Restore power/ground integrity: Repair damaged power feeds, sensor grounds, or shared grounds; perform verified repairs where voltage-drop testing shows excessive loss under load.
• Replace the exhaust gas temperature sensor: Replace only after circuit checks confirm the sensor is not responding correctly or fails inspection/testing per service information.
• Harness section replacement: Replace a damaged pigtail or harness segment if heat damage or repeated intermittent faults persist after connector repair.
• Module-side circuit repair: If all external wiring and the sensor test good, inspect for module connector damage; replace/control module service only when all other causes are eliminated and service information supports it.

Can I Still Drive With P2395?

You can often drive cautiously with P2395, but it depends on how the vehicle uses the cylinder 4 exhaust gas temperature sensor signal. Because this is a circuit fault, the system may substitute a default value and may limit performance to protect aftertreatment or engine components. Do not continue driving if you notice reduced power, severe drivability issues, warning messages related to engine protection, abnormal exhaust odor/smoke, or if the vehicle enters a protective mode; in those cases, have it inspected promptly.

What Happens If You Ignore P2395?

Ignoring P2395 can lead to persistent warning lights, recurring protective strategies, and reduced efficiency because the control system may not be able to trust exhaust temperature feedback. Over time, operating without reliable exhaust temperature sensing can contribute to higher exhaust temperatures or conservative fueling strategies, potentially accelerating wear of exhaust/aftertreatment components and making the fault harder to isolate if wiring damage progresses.

Last updated: February 16, 2026

Vehicles Commonly Affected by P2395

• Turbocharged engines: Applications that monitor exhaust temperature closely for component protection.
• Diesel-equipped vehicles: Systems using exhaust temperature sensing to support emissions control strategies.
• Vehicles with advanced aftertreatment: Configurations where exhaust temperature feedback influences catalyst or filter management.
• High-mileage vehicles: More likely to have harness fatigue, brittle insulation, or connector wear.
• Vehicles operated in harsh environments: Heat, road salt, water intrusion, or off-road debris can damage connectors and wiring.
• Vehicles with prior exhaust work: Repairs that disturb routing, heat shielding, or connector seating can create circuit issues.
• Short-trip duty cycles: Frequent heat cycling and condensation can accelerate corrosion at connectors.
• Heavy-load usage: Towing or sustained high load increases underbody temperatures and stress on nearby harnesses.

Use vehicle-specific service information to identify the exact sensor location and circuit routing for cylinder 4, then confirm the repair by verifying stable sensor circuit behavior and no returning DTCs after a complete drive cycle.