P2397 – Cylinder 6 Exhaust Gas Temperature Sensor Circuit

System: Powertrain | Standard: ISO/SAE Controlled | Fault type: Circuit | Location: Cylinder 6

Definition source: SAE J2012/J2012DA (industry standard)

DTC P2397 indicates the powertrain controller has detected an electrical fault in the circuit associated with the Cylinder 6 exhaust gas temperature (EGT) sensor. This code is about the sensor circuit (wiring, connectors, power/ground, signal integrity, and module input), not a confirmed mechanical problem by itself. Because EGT sensor designs, pinouts, and monitoring logic vary by vehicle, you should verify the exact sensor location, circuit description, and test specifications in the correct service information before testing or replacing parts.

What Does P2397 Mean?

P2397 – Cylinder 6 Exhaust Gas Temperature Sensor Circuit means the control module detected a fault in the electrical circuit for the exhaust gas temperature sensor assigned to Cylinder 6. Under SAE J2012 conventions, the code identifies the affected system and the specific monitored circuit; however, the code alone does not prove the sensor is bad. A correct diagnosis focuses on confirming circuit integrity (connections, wiring condition, proper power and ground paths where applicable, and a plausible sensor signal reaching the controller) using vehicle-specific service information.

Quick Reference

• System: Powertrain
• Official meaning: Cylinder 6 Exhaust Gas Temperature Sensor Circuit
• Standard: ISO/SAE controlled
• Fault type: Circuit
• Severity: MIL illumination is possible; the vehicle may limit certain powertrain functions tied to exhaust temperature management, with drivability impact varying by vehicle.

Symptoms

• MIL/Check engine: Warning light illuminated and P2397 stored as current or pending.
• Reduced performance: Possible torque limiting or reduced power strategy related to exhaust temperature protection (varies by vehicle).
• Regeneration issues: Regeneration or exhaust aftertreatment temperature control may be delayed, inhibited, or aborted (if equipped).
• Unstable readings: EGT-related live data may appear erratic, stuck, or implausible compared to other exhaust temperature inputs (if available).
• Fuel economy change: Efficiency may drop if the controller adopts a conservative fallback strategy for temperature management.
• Other codes: Additional exhaust temperature, sensor circuit, or aftertreatment-related DTCs may set alongside P2397.

Common Causes

• Sensor connector issue: Loose latch, bent pins, pushed-out terminals, moisture intrusion, or corrosion at the Cylinder 6 exhaust gas temperature (EGT) sensor connector.
• Harness damage: Chafed, melted, pinched, or stretched wiring near hot exhaust components causing shorts or opens in the EGT sensor circuit.
• Open circuit: Broken conductor inside insulation, poor crimp, or internal terminal fatigue creating an intermittent or hard open in the signal or return path.
• Short to ground or power: Signal or reference wire contacting ground, another circuit, or a power feed, skewing the circuit reading.
• Poor ground path: High resistance in the sensor ground/return (where applicable) due to corrosion, paint, loose fasteners, or shared ground issues (varies by vehicle).
• PCM/ECM connector fault: Water intrusion, fretting, poor pin fit, or damaged terminals at the control module connector affecting the EGT sensor circuit.
• Incorrect part or fitment: Wrong sensor type, mismatched connector, or improper routing/retention after service causing abnormal circuit behavior.
• Sensor internal fault: Internal EGT sensor failure causing an implausible circuit condition, typically confirmed only after wiring and connector checks.

Diagnosis Steps

Tools: a capable scan tool with live data and freeze-frame access, a digital multimeter, and vehicle-specific service information with connector pinouts and test procedures. Use back-probing leads or approved breakout adapters to avoid terminal damage. Basic hand tools for access and harness inspection are helpful. If available, use a data logger function to capture intermittent dropouts during a road test (varies by vehicle).

1. Confirm the code and context: Scan all modules for codes. Record freeze-frame data, conditions at set time, and any companion powertrain codes. Clear codes and see if P2397 resets immediately or after a drive cycle.
2. Identify the correct component: Using service information, locate the Cylinder 6 EGT sensor and confirm which connector/pins correspond to the EGT sensor circuit (pin assignments vary by vehicle).
3. Do a focused visual inspection: Inspect the sensor body and harness routing near the exhaust. Look for heat damage, abrasion points, missing clips, contact with sharp edges, or evidence of prior repairs.
4. Check connectors and terminals: Disconnect the EGT sensor connector and inspect for corrosion, moisture, bent pins, spread terminals, or a partially seated terminal. Verify the connector locks and strain relief are intact, then reconnect securely.
5. Wiggle test for intermittents: With the engine running (or key on if the test procedure calls for it), monitor the relevant EGT sensor PID(s) and gently wiggle the harness and connectors from the sensor back toward the main loom and module. Look for sudden dropouts or erratic changes that indicate a wiring/terminal fault.
6. Circuit integrity checks (power off): With ignition off and connectors unplugged as required by service information, test the harness for opens/shorts between the sensor connector and the control module connector. Check for continuity on each circuit and for unwanted continuity to ground or to other circuits.
7. Reference/ground verification (as applicable): With key on and the sensor connected or disconnected per service instructions, verify that the circuit provides the expected reference/supply and ground/return integrity. If equipped, confirm the ground path isn’t high resistance by checking for voltage drop under load (exact method varies by vehicle).
8. Voltage-drop testing under operating conditions: If service information supports it, perform voltage-drop tests across suspect connectors, splices, and ground points while the circuit is active. Excessive drop indicates unwanted resistance (corrosion, loose pins, damaged conductors) even when continuity tests look acceptable.
9. Sensor evaluation per service procedure: If wiring and connector tests pass, test the EGT sensor per the manufacturer procedure (often resistance/response checks or scan-tool plausibility checks). Replace the sensor only if it fails the specified test.
10. Module-side checks last: If the sensor and harness test good, inspect control module connectors for pin fit and corrosion and verify module power/ground integrity. Consider module fault only after all external circuit causes are eliminated.
11. Verify the repair: Clear codes, run the specified drive cycle or enable criteria, and confirm P2397 does not return. Review live data to ensure the EGT sensor signal behaves consistently during warm-up, steady cruise, and decel events.

Professional tip: Intermittent circuit issues often pass static continuity checks. Prioritize pin-fit inspection, harness movement testing, and voltage-drop testing under load, and capture live-data logs during the exact conditions shown in freeze-frame data. If the fault appears heat-related, focus inspection on sections of harness near the exhaust and on any areas with missing heat shielding or improper routing.

Possible Fixes & Repair Costs

Repair costs for P2397 vary widely because the root cause can be as simple as a connector issue or as involved as harness repairs, sensor replacement, or module-level concerns. Labor time also depends on sensor access and whether related wiring must be traced and repaired.

• Repair connector issues: Clean corrosion, correct terminal tension, repair pin fit, and ensure the connector is fully seated and locked.
• Repair wiring faults: Fix chafed insulation, broken conductors, heat-damaged sections, or shorts; restore proper routing and heat protection where applicable.
• Restore power/ground integrity: Repair opens in power/feed circuits, ground points, or splices; verify low resistance and stable supply under load.
• Replace the exhaust gas temperature sensor: Replace the Cylinder 6 EGT sensor only after circuit checks confirm the sensor is faulty or out of specification.
• Address exhaust heat-related damage: Replace melted conduit/loom, add appropriate shielding (as designed), and correct contact with hot components if it caused repeated circuit issues.
• Control module and programming actions: If service information directs and all circuit/sensor checks pass, perform required configuration, relearn, or module replacement steps (varies by vehicle).

Can I Still Drive With P2397?

You may be able to drive short distances with P2397, but it is best treated as a prompt-to-diagnose electrical fault because an exhaust gas temperature input can influence emissions control strategies and protection modes. If the vehicle enters reduced power, shows severe drivability issues, or you have warning indicators related to powertrain protection, avoid driving and arrange service to prevent heat-related component damage. If stalling, no-start, or any safety-critical warnings appear, do not drive.

What Happens If You Ignore P2397?

Ignoring P2397 can lead to recurring warning lights and failed emissions readiness checks, and it may cause the powertrain control system to rely on fallback values that reduce performance or efficiency. If the circuit fault prevents accurate exhaust temperature monitoring, the vehicle may be more likely to command protective strategies, and prolonged operation could contribute to overheating or accelerated wear of exhaust aftertreatment components depending on vehicle design.

Last updated: February 16, 2026

Vehicles Commonly Affected by P2397

• Vehicles equipped with EGT sensors: Powertrains that monitor exhaust gas temperature as part of emissions or component protection.
• Engines with cylinder-specific monitoring: Designs that track temperature feedback tied to specific cylinder bank or cylinder location (varies by vehicle).
• Turbocharged or high-load applications: Setups where exhaust temperature feedback is commonly used to manage protection strategies (varies by vehicle).
• Vehicles with complex exhaust aftertreatment: Systems that use temperature feedback for emissions control operation (varies by vehicle).
• High-mileage vehicles: Increased likelihood of harness fatigue, connector wear, and heat exposure over time.
• Vehicles used in harsh conditions: Frequent thermal cycling, road debris exposure, or vibration that can stress wiring and connectors.
• Recent exhaust or engine work: Increased chance of pinched wiring, misrouted harnesses, or partially seated connectors after service.
• Vehicles with prior harness repairs: Splices or repairs that may introduce resistance, poor crimping, or inadequate heat protection.

After repairs, confirm P2397 is resolved by clearing codes, running the appropriate drive cycle, and rechecking for pending or stored faults while monitoring the Cylinder 6 exhaust gas temperature sensor circuit for stable, repeatable behavior.