P2087 – Exhaust Gas Temperature Sensor Circuit Intermittent Bank 2 Sensor 2

P2087 is a powertrain diagnostic trouble code that points to a circuit-level problem in the emissions aftertreatment area, most often within the reductant/aftertreatment system on vehicles equipped with Selective Catalytic Reduction (SCR). SAE J2012 defines the overall DTC structure, but the exact component tied to P2087 can vary by make, model, and year. The only reliable way to confirm what your vehicle means by P2087 is to use scan data plus basic electrical checks (power, ground, reference voltage, and signal plausibility) at the affected circuit.

What Does P2087 Mean?

In SAE-style wording, P2087 is generally interpreted as a reductant/aftertreatment-related circuit reporting a high signal condition. “High” describes the signal behavior the Engine Control Module (ECM) / Powertrain Control Module (PCM) is seeing (voltage, frequency, or calculated value out of expected range), not a guaranteed failed part. Depending on the vehicle, the circuit may be commonly associated with a reductant pressure sensor, temperature sensor, level sensor circuit, or a related aftertreatment input.

This code is shown without an FTB (Failure Type Byte). If a hyphen suffix were present (for example, “-xx”), it would indicate a subtype that narrows the failure mode (such as signal range, rationality, or electrical fault category) per OEM interpretation. SAE J2012 formatting rules apply, and standardized DTC descriptions are published in the SAE J2012-DA digital annex; however, many powertrain sub-definitions still vary by manufacturer. What makes P2087 distinct is that it’s typically set when the module detects a signal biased too high compared to expected electrical limits or plausibility for the operating conditions.

Quick Reference

• Code: P2087
• System: Powertrain (emissions/aftertreatment, commonly SCR-related)
• Fault type: Circuit signal high (electrical/plausibility condition)
• What you’ll notice: MIL/check engine light, possible reduced power depending on strategy
• Commonly associated with: Reductant/aftertreatment sensors or their wiring (varies by vehicle)
• Best first checks: Freeze-frame review, live data plausibility, 5V reference integrity, sensor ground voltage drop

Real-World Example / Field Notes

In the bay, P2087 often shows up after recent service near the exhaust/aftertreatment area: harnesses get pulled tight, connectors don’t fully latch, or wiring rests against a hot heat shield. On some trucks and diesel SUVs, I’ve seen a “signal high” reading caused by moisture intrusion in a sensor connector that biases the signal upward, even though the sensor itself tests fine. Another pattern is a damaged shared 5-volt reference circuit: one compromised sensor can pull the reference line out of range and make an aftertreatment input look “high.” The quickest wins usually come from comparing scan-tool data to real electrical measurements at the connector under the same conditions.

Symptoms of P2087

• Check engine light illuminated, sometimes after a cold start or during steady cruising.
• Reduced power or torque management, especially under load or during highway acceleration.
• Fuel economy change (often worse) as the strategy compensates for an exhaust aftertreatment control issue.
• Aftertreatment message displayed (vehicle-dependent), such as warnings about emissions/aftertreatment operation.
• Rough running or unstable idle on some platforms if the control strategy alters combustion or exhaust temperature control.
• Regeneration behavior changes (more frequent/longer events or inhibited operation), depending on how the vehicle manages aftertreatment.
• Strong exhaust odor or unusual tailpipe smell when the exhaust aftertreatment system is not being controlled as intended.

Common Causes of P2087

Most Common Causes

• Wiring/connector issue in the circuit commonly associated with the exhaust aftertreatment reductant control (chafing, corrosion, water intrusion, loose pins)
• Low system voltage or charging issue affecting module outputs and actuator operation (weak battery, alternator undercharging)
• Faulty component commonly associated with reductant dosing control (vehicle-dependent), such as an actuator, driver-controlled valve, or dosing device that fails a commanded vs. observed plausibility check
• Exhaust aftertreatment system contamination or restrictions that make commanded control results implausible (crystallization, blockage, flow restriction)

Less Common Causes

• Poor power or ground to the control module responsible for aftertreatment management (Engine Control Module (ECM) / Powertrain Control Module (PCM) or a dedicated aftertreatment controller, depending on vehicle)
• Sensor feedback problem that causes the controller to judge the reductant control “range/performance” as implausible (feedback type varies by make/model/year)
• Network Communication issue causing incorrect or missing command/feedback correlation (Controller Area Network (CAN) related, vehicle-dependent)
• Possible internal processing or input-stage issue in the controlling module, considered only after external circuit, power/ground, and signal integrity tests pass

Diagnosis: Step-by-Step Guide

Tools you’ll use: a bidirectional scan tool with live data and output controls, a Digital Multimeter (DMM), a backprobe kit or piercing probes, a wiring diagram/service information, a battery charger or maintainer, a basic test light (used carefully), and if available a lab scope for command/signal verification and a smoke machine for checking leaks/ingress around connectors.

1. Confirm the customer complaint and capture freeze-frame data. Note battery voltage, coolant temperature, vehicle speed, and load when P2087 set. This helps you reproduce the exact enable conditions.
2. Verify the code is shown without a Failure Type Byte (FTB). Since you’re only seeing “P2087” with no suffix, you don’t have the subtype that would narrow whether it’s “signal too low/high,” “intermittent,” or another failure mode on some platforms.
3. Perform a quick visual inspection of the harness routing and connectors commonly associated with exhaust aftertreatment reductant control. Look for exhaust heat damage, rubbed-through insulation, corrosion, loose locks, or fluid/crystal residue that can wick into terminals.
4. Check system voltage and charging health: key-on engine-off and engine-running. If voltage is unstable or low, correct that first because it can create false “range/performance” results.
5. On the scan tool, review live data related to aftertreatment/reductant control (names vary by vehicle). Look for commanded state vs. actual/feedback values. A large mismatch is a clue, but you still need circuit testing to avoid guessing the component.
6. Use bidirectional controls (if supported) to command the reductant control function through several steps while monitoring the response. If the command changes but the feedback doesn’t, move to electrical checks; if neither changes, confirm controller enable conditions and power/ground.
7. Electrical checks at the suspect actuator/device connector: verify power feed(s) and ground integrity under load. Use a voltage drop test on grounds and power while the device is commanded on (when safe/possible). High voltage drop indicates resistance in wiring or connections.
8. Check control and signal integrity: with a DMM or lab scope, verify the controller is providing an appropriate command signal (duty cycle/voltage pattern depends on design) and that the circuit isn’t shorted to power/ground. Wiggle-test the harness while watching for dropouts.
9. If wiring and command/signal look correct at the component but the response is implausible, confirm the component’s mechanical condition (restriction, sticking, contamination) in a way appropriate to the design. Only after that should you consider a controller-side driver issue.

Professional tip: When chasing a “range/performance” P2087, prioritize correlation testing—command the function with the scan tool and verify (1) stable battery/charging voltage, (2) low voltage drop on power/ground under load, and (3) clean, repeatable command waveform at the component; if all three are good and the response is still implausible, you’ve earned the right to suspect the component or, last, a possible module input/driver issue.

Possible Fixes & Repair Costs

Fixing P2087 correctly depends on what your tests prove about the exhaust-gas temperature signal and its supporting circuits (power, ground, reference, and signal integrity). Costs vary widely by vehicle because exhaust layouts, sensor access, and wiring routing near hot components differ by make/model/year.

• Low ($0–$60): Repair a loose connector, reseat terminals, clean light corrosion, secure a harness away from the exhaust, or replace damaged heat shielding/loom. Justified when a wiggle test changes the signal or you find obvious heat damage/chafing and continuity/voltage drop tests confirm it.
• Typical ($120–$450): Replace an Exhaust Gas Temperature (EGT) sensor (commonly associated with P2087 on many applications) after confirming the sensor’s response is implausible versus actual temperature change or its resistance/voltage behavior is out of spec compared to known-good behavior. Include labor for access and seized fasteners.
• High ($500–$1,500+): Harness section repair, exhaust component removal for access, or (only after external wiring and sensor signal tests pass) addressing a possible internal processing or input-stage issue in the Powertrain Control Module (PCM). High cost is justified when you can prove a correct signal at the PCM input but the PCM still flags P2087.

Can I Still Drive With P2087?

Sometimes you can, but you should treat P2087 as a warning that the PCM is not happy with an exhaust temperature signal range it uses for emissions and turbo/aftertreatment protection strategies (exact strategy varies by vehicle). If you notice reduced power, harsh drivability changes, smoke, strong exhaust smell, or a very hot odor, limit driving and avoid heavy load/towing until you can test it. Continued operation can increase heat stress and emissions-system risk.

What Happens If You Ignore P2087?

Ignoring P2087 can lead to chronic derate/limp behavior, poor fuel economy, and higher exhaust temperatures because the PCM may fall back to conservative default models when it can’t trust the sensor signal. Over time, that can accelerate wear on hot-side components (wiring, connectors, sensors, and nearby exhaust hardware) and may contribute to aftertreatment inefficiency on vehicles that use exhaust temperature feedback for protection and control.

Related Sensor Exhaust Codes

Compare nearby sensor exhaust trouble codes with similar definitions, fault patterns, and diagnostic paths.

• P2085 – Exhaust Gas Temperature Sensor Circuit Intermittent Bank 1 Sensor 2
• P2083 – Exhaust Gas Temperature Sensor Circuit Intermittent Bank 2 Sensor 1
• P2081 – Exhaust Gas Temperature Sensor Circuit Intermittent Bank 1 Sensor 1
• P2084 – Exhaust Gas Temperature Sensor Circuit Range/Performance Bank 1 Sensor 2
• P2082 – Exhaust Gas Temperature Sensor Circuit Range/Performance Bank 2 Sensor 1
• P2080 – Exhaust Gas Temperature Sensor Circuit Range/Performance Bank 1 Sensor 1

Key Takeaways

• System-level meaning: P2087 points to an exhaust gas temperature sensor circuit “range/performance” type problem, not an automatic sensor replacement.
• Definition can vary: SAE J2012 defines the DTC structure, but exact component/application details can differ by make/model/year—confirm with scan data and basic electrical tests.
• Test first: Verify power/ground/reference (as applicable), signal integrity, and plausibility versus real temperature change before buying parts.
• Heat-related wiring is common: Harness damage near the exhaust is a frequent root cause; use wiggle/heat-soak checks and voltage-drop testing.
• Module last: Consider PCM input-stage issues only after you prove the sensor and wiring deliver a correct signal to the PCM.

Vehicles Commonly Affected by P2087

P2087 is commonly seen on turbocharged gasoline direct-injection platforms and on light-duty diesel applications where exhaust temperature feedback is frequently associated with protection and emissions strategies. It’s often reported on vehicles from Ford, Volkswagen/Audi, and GM, largely because these architectures pack wiring and sensors tightly around high-heat exhaust and turbo components. That heat exposure increases the chance of connector fretting, insulation brittleness, and signal drift that can trigger a range/performance judgment.

FAQ

Can P2087 be caused by wiring even if the sensor is new?

Yes. A new sensor won’t fix a signal that’s being corrupted by high resistance in the connector, a partially broken conductor, heat-damaged insulation, or a poor ground path. Confirm by measuring voltage drop on the ground side (where applicable), checking continuity under load, and doing a wiggle test while watching live data. If the signal jumps or goes implausible during harness movement, focus on wiring/terminals.

Is P2087 the same on every make and model?

No. SAE J2012 defines how the code is formatted and categorized, but many OEMs map the same base code to different exhaust temperature sensor locations or strategies depending on the engine and exhaust configuration. To confirm what your vehicle means, read the OEM code description with a capable scan tool, identify which EGT PID is implicated, and verify the circuit with basic electrical tests (power/ground/reference and signal plausibility).

Can I diagnose P2087 with a basic multimeter?

Often, yes—at least to narrow it down. A Digital Multimeter (DMM) can verify power/ground integrity, check for opens/shorts, and measure resistance on sensor circuits where applicable. The key is to pair meter checks with scan data: watch the EGT reading for plausibility during warm-up and a brief load change. If the PID is irrational but wiring checks good, the sensor is more suspect.

Will clearing P2087 fix it if the light turns off?

Clearing the code only resets the fault memory; it doesn’t fix the underlying range/performance condition. If the PCM sees the same implausible signal again during its monitor run, P2087 will return. After clearing, use a controlled road test and monitor live EGT data to see if the value tracks smoothly with temperature changes. If it fails again, you need circuit and sensor verification, not repeated clears.

Can an exhaust leak cause P2087?

It can, depending on where the leak is and how the vehicle uses exhaust temperature feedback. A leak upstream can change local gas flow and heat distribution, making the measured temperature behave unexpectedly compared to modeled expectations, which may trip a range/performance decision. Confirm by inspecting for soot trails, ticking noises, and loose fasteners, then compare EGT behavior to engine load changes. Fix the leak only if testing supports it.