P2489 – EGT Sensor Circuit Intermittent (Bank 2 Sensor 2)

System: Powertrain | Standard: ISO/SAE Controlled | Fault type: Circuit Intermittent | Location: Bank 2, Sensor 2

Definition source: SAE J2012/J2012DA (industry standard)

P2489 indicates the powertrain controller detected an intermittent electrical signal condition in the exhaust gas temperature (EGT) sensor circuit for Bank 2 Sensor 2. “Intermittent” means the fault is not consistently present; it may appear only during certain temperatures, vibration levels, load conditions, or after harness movement. Because EGT sensor location, wiring routing, and monitoring strategy vary by vehicle, confirm sensor identification (bank and sensor position) and exact test procedures using the appropriate service information. Treat the code as an electrical/signal integrity issue until testing proves a component fault.

What Does P2489 Mean?

P2489 means the vehicle has detected an EGT Sensor Circuit Intermittent (Bank 2 Sensor 2) condition. In practical diagnostic terms, the controller is seeing an EGT sensor circuit signal that periodically drops out, spikes, or becomes unstable compared to what it expects from a steady electrical connection. This is a circuit integrity problem category (intermittent), typically pointing first to wiring, connector fitment, terminal tension, corrosion, or an internally failing sensor that intermittently opens or shorts. SAE J2012 defines standardized DTC structure and naming so the fault description maps to a specific monitored condition.

Quick Reference

• System: Powertrain
• Official meaning: EGT Sensor Circuit Intermittent (Bank 2 Sensor 2)
• Standard: ISO/SAE Controlled
• Fault type: Circuit Intermittent
• Severity: MIL illumination is possible; depending on strategy the vehicle may limit performance to protect emissions and exhaust components if temperature feedback is unreliable.

Symptoms

• MIL/Check engine: Warning lamp on, sometimes after multiple drive cycles due to the intermittent nature.
• Intermittent power reduction: Temporary reduced power or torque management when the controller cannot trust EGT feedback.
• Unstable temperature reading: Live data may show Bank 2 Sensor 2 EGT value flickering, dropping out, or jumping unexpectedly.
• Inconsistent regeneration behavior: Regeneration requests or completion may be delayed/aborted when EGT input is erratic (when applicable to vehicle design).
• Poor driveability during specific conditions: Symptoms may appear only under vibration, after heat soak, or during acceleration/cruise transitions.
• Additional related codes: Other temperature-sensor or circuit-related DTCs may set if the intermittent circuit disrupts plausibility checks.

Common Causes

• Intermittent connector contact: Loose terminal tension, poor pin fit, partially seated connector, or vibration-related contact loss at the EGT sensor or harness connector.
• Harness damage near hot components: Heat-soaked insulation, brittle wiring, or chafing where the harness routes near exhaust parts, shields, brackets, or underbody clips.
• Corrosion or contamination: Moisture intrusion, oxidation, or debris in terminals causing momentary signal dropouts or noise.
• Broken/partially broken conductor: Internal wire break that opens only when the harness is flexed, moved, or thermally expanded.
• Intermittent short between circuits: Occasional contact between signal and power/ground/adjacent wires due to rubbed-through insulation or crushed sections.
• Sensor internal intermittent fault: EGT sensor element or internal connection that intermittently opens or becomes noisy with temperature or vibration.
• Reference/return integrity issue: Intermittent loss of sensor feed, return, or shared circuit integrity (varies by vehicle), including splice or ground point issues affecting the sensor circuit.
• PCM/ECM connector or pin issue: Backed-out terminals, fretting, or intermittent contact at the control module connector for the Bank 2 Sensor 2 EGT input circuit.

Diagnosis Steps

Tools that help include a scan tool capable of reading live data and freeze-frame, a multimeter for voltage-drop and continuity checks, and basic back-probing or breakout leads. Depending on vehicle design, a wiring diagram/service information is essential to identify the correct Bank 2 Sensor 2 circuit, connector pinouts, and routing. If available, a graphing function or data logger is useful for capturing intermittent dropouts during a road test.

1. Confirm the DTC and context: Verify P2489 is present. Record freeze-frame data, ambient conditions, and any related DTCs. Clear codes only after documentation so you can compare what changes after testing.
2. Check for related faults: Look for other sensor circuit intermittent, power supply, or ground-related DTCs that could point to a shared harness, splice, or connector issue. Address obvious shared-circuit problems first if present.
3. Identify the correct sensor and bank: Using service information, locate the EGT sensor designated Bank 2 Sensor 2 and trace its harness routing to the next connector and to the control module. Bank and sensor numbering varies by vehicle; don’t rely on assumptions.
4. Visual inspection (cold and hot-soak aware): Inspect the harness and connector bodies for melting, contact with exhaust, broken clips, tight bends, pinch points, or rub-through. Pay special attention to sections near heat shields, brackets, and where the harness transitions between rigid supports and free span.
5. Connector/terminal inspection: Disconnect the sensor connector (as applicable) and inspect for corrosion, moisture, spread terminals, pushed-out pins, or damaged seals. Verify the connector seats positively and that any secondary locks are intact. Repair terminal fit issues as needed.
6. Wiggle test with live data: Reconnect and monitor the EGT-related PID(s) and/or circuit status on the scan tool. With the engine running (or key-on per service info), gently flex the harness at the sensor, along the routing, and at intermediate connectors. If the reading drops out, spikes, or the fault resets, isolate the exact movement point.
7. Harness continuity and intermittent open checks: With the circuit safely powered down as required, perform continuity checks end-to-end for the signal, feed, and return circuits per the wiring diagram. While measuring, flex the harness and connectors to reveal intermittent opens that don’t show up when static.
8. Short-to-ground/short-to-power checks: Test each circuit for unintended continuity to ground or to power (per service procedure). Flex and tap suspect harness areas during the test to reproduce intermittent contact between conductors.
9. Voltage-drop testing under load: With the system operating (as applicable), perform voltage-drop tests across suspected connectors, splices, and ground/return paths related to the EGT sensor circuit. Intermittent faults often appear as momentary increased drop when the harness is moved or when electrical loads change.
10. Live-data logging road test: If safe and practical, log EGT sensor data and engine operating conditions during a drive that replicates the freeze-frame environment (load, speed, temperature). Look for brief signal dropouts/noise that coincide with bumps, vibration, or heat soak, which can pinpoint location-dependent wiring issues.
11. Sensor evaluation after circuit integrity is verified: If wiring, connectors, power/return integrity, and module pin fit all test good, evaluate the EGT sensor for an internal intermittent issue using the service-recommended method (varies by vehicle). Replace the sensor only after confirming the circuit is stable.
12. Verification: After repairs, clear codes and repeat the conditions that previously set the fault. Confirm the EGT signal remains stable in live data and that P2489 does not return after an appropriate drive cycle.

Professional tip: Intermittent circuit faults are often easiest to catch when you reproduce the exact trigger condition—heat soak, vibration, or harness position. Focus on “transition zones” (near connectors, splices, and where the harness changes direction or is clipped to the body). If the issue appears only while driving, use live-data logging and then inspect the harness at the points where the dropout timestamp matches bumps or load changes.

Possible Fixes & Repair Costs

Repair cost for P2489 varies widely by vehicle and depends on what testing confirms, parts access, and labor time. Because this is a circuit intermittent fault, the correct fix is the one that eliminates the unstable signal rather than replacing parts by guesswork.

• Repair damaged wiring: Restore chafed, stretched, melted, or pinched sections in the EGT sensor circuit for Bank 2 Sensor 2, then secure the harness to prevent repeat vibration-related opens.
• Service connector and terminals: Clean contamination, correct moisture intrusion, address poor terminal tension/pin fit, and repair backed-out or spread terminals that can create intermittent contact.
• Resolve power/ground integrity issues: Repair shared grounds, splices, or power feeds that intermittently drop out under load; correct any corrosion or loose fasteners found during voltage-drop testing.
• Replace the EGT sensor (Bank 2 Sensor 2): Replace only after confirming the sensor’s signal becomes unstable independent of wiring movement and connector condition (varies by vehicle design).
• Correct routing/heat shielding: Re-route away from heat sources and install/repair protective shielding or loom where excessive heat cycles can damage insulation and cause intermittent opens/shorts.
• Repair exhaust-related interference: Fix contact points where the harness or connector is rubbed by exhaust components or brackets, creating intermittent faults as the powertrain moves.
• Update/repair control module connections: If testing shows the issue is at the module-side connector (poor pin fit or fretting), repair terminals or connector body as required; replace modules only if service information and testing justify it.

Can I Still Drive With P2489?

You may be able to drive short distances if the vehicle feels normal, but treat P2489 as a warning that the EGT Sensor (Bank 2 Sensor 2) signal is intermittently unreliable. Intermittent faults can change quickly with heat, vibration, or moisture, potentially triggering reduced power strategies or additional warnings. Do not continue driving if you notice reduced power, heavy hesitation, stalling, a no-start condition, abnormal exhaust smell/heat, or any brake/steering warnings; arrange diagnosis as soon as possible and verify guidance in service information for your platform.

What Happens If You Ignore P2489?

Ignoring P2489 can lead to recurring warning lights and intermittent drivability changes depending on how the powertrain uses EGT feedback. Because the circuit fault is intermittent, the problem can be difficult to reproduce and may worsen over time as terminals loosen further or wiring damage spreads. In some calibrations, unreliable EGT input may cause conservative control actions that reduce performance or fuel efficiency, and it can complicate diagnosis of related exhaust-temperature or emissions-control concerns by introducing inconsistent data.

Last updated: February 18, 2026

Vehicles Commonly Affected by P2489

• Vehicles equipped with an EGT sensor after the catalyst: Configurations that monitor exhaust temperature downstream (sensor location varies by vehicle).
• Engines with multiple exhaust banks: Applications using Bank 2 identification where sensor placement is bank- and position-specific.
• Turbocharged applications: Higher exhaust heat and tight packaging can accelerate harness and connector heat-related issues (varies by vehicle).
• Vehicles with underbody exhaust routing near harness runs: Exposure to road debris, water, and salt can contribute to intermittent terminal contact.
• High-mileage vehicles: Repeated heat cycles and vibration can loosen terminals and fatigue conductors over time.
• Vehicles used in frequent stop-and-go operation: Thermal cycling and vibration can make marginal connections show up as intermittent faults.
• Vehicles operating in wet or corrosive environments: Moisture intrusion and corrosion can create intermittent resistance changes at connectors and splices.
• Recently serviced exhaust or sensor-related repairs: Misrouted harnesses, partially seated connectors, or disturbed clips can cause intermittent contact.

For best results, reproduce the fault during testing (heat/vibration conditions) and confirm the repair with a road test and follow-up scan to ensure the intermittent circuit condition does not return.