P2393 – Cylinder 2 Exhaust Gas Temperature Sensor Circuit

System: Powertrain | Standard: ISO/SAE Controlled | Fault type: Circuit | Location: Cylinder 2

Definition source: SAE J2012/J2012DA (industry standard)

P2393 is a powertrain diagnostic trouble code that indicates the engine control module has detected a problem in the Cylinder 2 exhaust gas temperature (EGT) sensor circuit. This is an electrical circuit-related fault, not a confirmed sensor or exhaust hardware failure by itself. The EGT signal is typically used to help monitor exhaust temperature conditions that can affect emissions and component protection strategies. Code setting criteria, enabling conditions, and the exact sensor location or wiring layout can vary by vehicle, so always verify the specific circuit description, connector views, and test specifications in the applicable service information.

What Does P2393 Mean?

P2393 means Cylinder 2 Exhaust Gas Temperature Sensor Circuit. Based on the official definition/description, the fault is tied to the electrical circuit for the EGT sensor associated with cylinder 2, as interpreted by the powertrain control system. In SAE J2012 terms, this points to a circuit-level issue such as an open, short, poor connection, power/ground problem, or signal integrity concern affecting the EGT sensor input the controller expects to see. The code alone does not prove the sensor is bad; it only confirms the circuit input is not behaving as required under the controller’s diagnostic tests.

Quick Reference

• System: Powertrain
• Official meaning: Cylinder 2 Exhaust Gas Temperature Sensor Circuit
• Standard: ISO/SAE controlled
• Fault type: Circuit
• Severity: MIL may illuminate; engine protection or emissions strategies may be affected, potentially causing reduced performance depending on how the control system substitutes the missing/invalid signal.

Symptoms

• Check engine light: MIL illuminated with P2393 stored as current or pending.
• Reduced power: Limited torque or protective control actions if the system relies on EGT input for temperature-based protection.
• Driveability changes: Hesitation, uneven response, or altered shifting behavior on some platforms due to torque management interactions (varies by vehicle).
• Regeneration issues: In systems that use EGT for aftertreatment temperature control, regeneration may be inhibited or interrupted (varies by vehicle design).
• Poor fuel economy: Increased consumption if the controller uses conservative fallback strategies.
• Additional DTCs: Related sensor circuit or plausibility codes may appear if the controller detects correlated input conflicts.

Common Causes

• Connector issue: Loose, partially seated, contaminated, or heat-damaged connector at the Cylinder 2 exhaust gas temperature (EGT) sensor.
• Harness damage: Melted insulation, chafing, pinched wiring, or contact with hot exhaust components causing circuit faults.
• Open circuit: Broken conductor inside the harness, poor splice, or terminal crimp failure leading to loss of signal continuity.
• Short to ground: Signal or supply conductor contacting chassis/engine ground due to insulation breakdown.
• Short to power: Signal conductor shorted to a power feed within the harness or at a rubbed-through point.
• Poor terminal fit: Spread terminals, pushed-out pins, corrosion, or fretting causing intermittent contact and unstable readings.
• Ground path problem: High resistance or open ground return (where applicable by vehicle design) affecting sensor circuit integrity.
• Sensor element failure: Internal EGT sensor electrical failure (open/short/high resistance) confirmed only through testing.
• Control module/driver issue: Rare internal fault in the control module input circuit or bias/reference circuit (varies by vehicle).

Diagnosis Steps

Tools: a scan tool with live data and freeze-frame access, a digital multimeter, and vehicle-specific service information for wiring diagrams, pinouts, and test procedures. Helpful additions include back-probing pins, a breakout lead set, basic hand tools for access, and materials to secure/heat-shield the harness after repair. Use appropriate personal protection when working near the exhaust.

1. Confirm the code and context: Scan for DTCs, record freeze-frame data, and note any companion codes that could influence EGT readings or circuit monitoring. Clear codes only after data is saved.
2. Identify the correct component and bank/cylinder location: Using service information (varies by vehicle), verify the physical location of the Cylinder 2 EGT sensor and the connector/harness routing to avoid testing the wrong sensor.
3. Initial visual inspection (key off): Inspect the EGT sensor connector, locking tabs, terminal condition, and harness routing. Look for melted sections, abrasion, contact with the exhaust, missing clips, or signs of water intrusion.
4. Connector/terminal check: Disconnect the sensor and inspect for bent, pushed-out, corroded, or spread terminals. Confirm proper pin tension/fit and that seals are intact; repair terminal issues before deeper electrical testing.
5. Live-data plausibility check: With the scan tool, observe the Cylinder 2 EGT parameter (and any related EGTs, if available) at idle and during a controlled warm-up. Look for erratic jumps, dropouts, or an implausible fixed value that suggests a circuit fault. Log data so brief faults are captured.
6. Wiggle test while logging: While monitoring the live-data PID and/or fault status, gently wiggle the connector and move the harness along its routing (especially near heat shields and sharp edges). If the value drops out or spikes, suspect intermittent wiring/terminal contact at the disturbed area.
7. Power/ground/reference verification: With the sensor disconnected and ignition on (as applicable by design), use the wiring diagram to verify the presence of the correct feed/reference and ground at the harness side. If power or ground is missing, trace the circuit back to the source and check for opens, shorts, or shared circuit issues.
8. Continuity and short checks (key off): Using the multimeter and service pinouts, check continuity end-to-end for each circuit between the sensor connector and the control module connector. Then check each circuit for shorts to ground and shorts to power. Repair any open/high resistance or short found.
9. Voltage-drop testing under load: Where service procedures allow, load the circuit and perform voltage-drop testing across suspect connectors, splices, and grounds to find high resistance that may not show up on a simple continuity test. Focus on areas exposed to heat and vibration.
10. Sensor electrical verification: Test the EGT sensor electrically using the manufacturer’s procedure (varies by sensor type). Compare results to specifications; replace the sensor only if it fails the specified checks and the harness/circuits test good.
11. Control module input isolation (only after wiring/sensor checks): If the harness and sensor test good but the fault persists, follow service information to check the control module pin condition and input behavior. Verify there are no backed-out pins, water intrusion, or terminal damage before considering module-related faults.
12. Verification drive: After repairs, clear DTCs, run any required relearn/monitor procedure (varies by vehicle), and road test under conditions that enable the monitor. Recheck for pending codes and review the data log to confirm the signal is stable.

Professional tip: If P2393 is intermittent, prioritize a heat- and vibration-focused inspection: check harness sections near the exhaust, heat shields, and retention points first, then reproduce the fault with a controlled wiggle test while recording live data. Confirm repairs by ensuring the harness is resecured and protected from heat so the same failure mode does not return.

Possible Fixes & Repair Costs

Repair cost for P2393 varies widely by vehicle and depends on what testing confirms (sensor vs wiring vs control-module fault), how accessible the sensor and harness are, and whether heat-related connector damage requires additional parts or labor.

• Repair wiring faults: Restore continuity by repairing open circuits, chafed insulation, or heat-damaged conductors in the Cylinder 2 exhaust gas temperature sensor circuit.
• Clean and secure connectors: Remove corrosion/contamination, address moisture intrusion, correct poor pin fit, and ensure connectors are fully seated and locked.
• Restore power/ground integrity: Repair missing feed, poor ground, or excessive voltage drop found during circuit testing (including ground straps where applicable).
• Replace the exhaust gas temperature sensor: Only after verifying the sensor is out of specification or fails functional checks and the circuit tests good.
• Repair harness routing/heat shielding: Re-route or protect wiring found too close to hot components to prevent recurring insulation breakdown.
• ECM/PCM connector service: If terminal drag, bent pins, or intermittent contact is confirmed at the controller interface, repair terminals or connector bodies as required.
• Control module replacement/programming: Consider only after all circuit and sensor checks pass and service information supports module-level diagnosis.

Can I Still Drive With P2393?

You can often drive short distances with P2393 if the vehicle runs normally, but treat it as a powertrain fault that may trigger the MIL and protective strategies (such as reduced power) depending on vehicle design. If you notice severe drivability changes, reduced power, warning messages, harsh running, stalling, or any brake/steering warnings, do not continue driving—stop safely and diagnose the circuit to prevent further complications.

What Happens If You Ignore P2393?

Ignoring P2393 can lead to persistent MIL illumination and failed emissions readiness, and on some platforms it may cause the engine to default to substitute values for exhaust temperature control. That can reduce performance or fuel efficiency and may contribute to poor aftertreatment management. If the underlying issue is an intermittent harness or connector problem, it may worsen over time and become harder to diagnose.

Last updated: February 16, 2026

Vehicles Commonly Affected by P2393

• Engines with exhaust gas temperature sensing: Systems that monitor exhaust temperature for emissions or protection strategies.
• Turbocharged applications: Platforms that use exhaust temperature feedback to manage protection limits (varies by vehicle).
• Aftertreatment-equipped vehicles: Configurations that rely on exhaust temperature inputs to support emissions system operation (varies by vehicle).
• High-heat engine bays: Installations where the sensor harness runs near hot exhaust components, increasing insulation and connector stress.
• Frequent short-trip use: Conditions that increase condensation/corrosion potential at connectors and encourage intermittent electrical contact issues.
• High-vibration duty cycles: Use patterns that can loosen terminals or fatigue wiring near mounting points and brackets.
• Older wiring looms: Vehicles where aging harness materials can become brittle and crack from repeated heat cycles.
• Recent exhaust work: Vehicles that have had components removed/installed near the sensor circuit where connectors may be left loose or wiring pinched.

Verify all testing and repair steps against the correct service information for your exact vehicle configuration before replacing parts or performing module-level repairs.