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Results are grouped by useful content—not by paid placement or guessed parts. Describe the symptom naturally; IAR recognizes common alternate wording while keeping exact codes and vehicle details precise.
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The control module detected cooling-system temperature behavior outside its expected performance range. The code does not by itself identify a thermostat, coolant-temperature sensor, fan, coolant level, radiator, water pump, or other failed part.
Generic codeThe engine did not reach the expected temperature behavior under the monitor’s conditions. The thermostat is one possibility, not the only one.
Generic codeThe control module detected coolant-temperature sensor behavior outside the expected range or performance relationship. The code does not by itself prove the sensor, wiring, connector, actual engine temperature, or control strategy as the cause.
Generic codeThe control module detected a coolant-temperature sensor circuit signal in a low range for the vehicle’s monitoring strategy. The code does not by itself prove the sensor, wiring, connector, or engine temperature is the cause.
Generic codeThe control module detected a coolant-temperature sensor circuit signal in a high range for the vehicle’s monitoring strategy. The code does not by itself prove the sensor, wiring, connector, or engine temperature is the cause.
Generic codeThe generic EVAP monitor reported a system-level malfunction. The code identifies the monitored emissions system, not a failed cap, valve, hose, canister, sensor, or other specific part.
Generic codeThe control system reached a lean-condition diagnostic threshold for Bank 1. The data does not by itself prove a vacuum leak, MAF sensor, or fuel pump.
Generic codeThe control system reached a lean-condition diagnostic threshold for Bank 2. The data does not by itself prove a vacuum leak, MAF sensor, oxygen sensor, or fuel-delivery failure.
Generic codeThe control system reached a rich-condition diagnostic threshold for Bank 1. The data does not by itself prove an injector, fuel-pressure, MAF sensor, or oxygen-sensor failure.
Generic codeThe control system reached a rich-condition diagnostic threshold for Bank 2. The data does not by itself prove an injector, fuel-pressure, MAF sensor, or oxygen-sensor failure.
Generic codeThe generic EVAP monitor detected purge-flow behavior outside its expected strategy. The code does not prove the purge valve itself is failed; the flow path, sealing, sensing, electrical control, and vehicle-specific monitor conditions still have to be tested.
Generic codeThe catalyst monitor determined that Bank 1 oxygen-storage performance was below its calibrated threshold. The code alone does not prove the converter is the original cause.
Generic codeThe catalyst monitor determined that Bank 2 oxygen-storage performance was below its calibrated threshold. The code alone does not prove the converter is the original cause.
Generic codeThe generic DTC identifies a purge-control valve circuit condition. It does not prove the purge valve itself is mechanically or electrically failed; wiring, connectors, power/ground, driver control, and exact circuit design must be tested.
Generic codeThe generic DTC identifies an open-circuit condition in the purge-control valve circuit. It narrows the electrical fault type, but it still does not prove the purge valve itself is the failed part.
Generic codeThe generic DTC identifies a short-circuit condition in the purge-control valve circuit. It does not establish whether the short is in the device, harness, connector, supply/control path, or module driver.
Generic codeThe generic DTC identifies a vent-control circuit malfunction. It does not identify whether the fault is the vent device, wiring, connector, power/ground, control driver, or another exact-vehicle circuit condition.
Generic codeThe generic DTC identifies an open-circuit condition in the EVAP vent-control circuit. It does not prove the vent valve or solenoid itself is failed.
Generic codeThe generic DTC identifies a short-circuit condition in the EVAP vent-control circuit. It does not identify the exact location of the short or prove the vent device itself is the cause.
Generic codeThe generic DTC identifies a malfunction in the EVAP vent valve or solenoid control circuit. It is a circuit-level finding, not proof that the vent valve or solenoid should be replaced.
Generic codeThe EVAP monitor detected a small-leak or sealing condition. The code does not identify the physical leak location or prove which component failed.
Generic codeThe EVAP monitor detected a very small leak or inability to maintain the expected seal. The code does not identify the leak location or prove a specific valve, cap, hose, or canister failed.
Generic codeThe EVAP monitor detected a large-leak or inability-to-seal condition. It does not identify where the leak or control fault is located.
Generic codeThe cooling system moves heat away from the engine and releases it through controlled coolant flow and airflow. Overheating demands immediate safety judgment before diagnosis.
System guideHVAC comfort depends on airflow, heat exchange, temperature control, doors, sensors, and—for air conditioning—a sealed refrigerant system. Warm air alone does not identify a failed compressor.
System guideThe starting system must authorize the request and deliver high current long enough to rotate the engine. A no-crank condition is different from an engine that cranks normally but does not run.
System guideThe charging system supports electrical loads and restores energy to the battery. Modern output can change intentionally, so one voltage reading does not automatically prove an alternator is good or bad.
System guideThe brake system converts motion into heat and controls wheel deceleration. Noise, vibration, pull, warning lamps, and pedal changes require inspection of the whole system rather than one assumed axle or part.
System guideThe fuel system stores and meters fuel under controlled conditions. A no-start, lean code, odor, or hesitation can involve supply, command, air measurement, electrical control, mechanical condition, or vapor management.
System guideA transmission changes the relationship between engine or motor speed and wheel speed. Shift concerns can originate in fluid condition, controls, sensors, engine operation, mounts, driveline parts, or internal wear.
System guideEmissions systems control combustion byproducts and fuel vapor while monitoring performance. A code reports what a monitor detected; it does not automatically name the part that caused the result.
System guideAWD and 4WD systems distribute torque among driven wheels. Binding, noise, warning messages, and fluid leaks can involve tire mismatch, joints, bearings, clutches, gears, controls, or incorrect operating mode.
System guideUse controlled pressure on a cool system to investigate leaks without opening a hot, pressurized cooling circuit.
Test-first procedureCompare operating pattern, temperature data, and airflow evidence without applying a universal gauge, infrared, or fan rule.
Test-first procedureCheck whether the vehicle is replenishing electrical energy under its intended operating strategy instead of applying one universal voltage rule.
Test-first procedureSeparate state of charge, battery condition, and connection problems before blaming the starter or alternator.
Test-first procedureInvestigate key-off battery drain only after the vehicle has entered its correct sleep state and the evidence is preserved.
Test-first procedureSeparate start-request, interlock, cable, ground, solenoid, and starter-motor evidence before bypassing the circuit or replacing the starter.
Test-first procedureSeparate vibration caused by brake application from a shake that follows road speed before choosing a brake, wheel, tire, hub, or suspension path.
Test-first procedureThe engine or cooling system is reporting excessive temperature or a related protection condition. The warning does not identify whether the cause is coolant loss, airflow, circulation, control, or internal leakage.
Stop and assessThe vehicle has detected a charging-system or electrical-generation concern. The battery symbol does not by itself prove the battery failed.
Assess promptlyThe engine or emissions control system has detected a condition that should be investigated. The lamp alone does not identify a failed part.
Assess promptlyThe lamp may indicate an applied parking brake, low fluid, hydraulic concern, or another vehicle-specific brake-system condition. The symbol alone cannot prove the brakes are safe.
Stop and assessThe anti-lock braking system has reported a fault or has been disabled. Base braking may behave differently, and the exact effect depends on the vehicle and any other warning lamps.
Assess promptlyThe traction-control, stability-control, or related chassis-control system has reported a fault, has been switched off, or is actively intervening. The lamp alone does not identify a failed sensor or module.
Assess promptlyThe system may be reporting low tire pressure, a sensor/communication problem, or a relearn/registration condition. Measure the tires before diagnosing electronics.
CautionThe supplemental restraint system has detected a fault or is not fully available. A lamp is not a reason to probe connectors or install a used restraint component.
CautionTreat active hot coolant loss as a burn and overheating hazard, then inspect the cooled system to separate external leakage, cap/sealing concerns, trapped air, and possible internal loss.
intermediateTreat overheating as a stop-and-assess condition, then separate coolant loss, airflow, circulation, control, and combustion concerns.
professional recommendedCabin heat complaints can come from engine temperature, coolant level/circulation, airflow, blend-door/control operation, or an electric heat source on some vehicles.
intermediateSeparate airflow, temperature, humidity, glass, control-door, blower, and cooling-system evidence before driving in conditions where the windshield cannot stay clear.
intermediateAn EVAP code identifies a monitored vapor-control condition, but the useful next test depends on whether the evidence points to a leak/sealing fault, purge-flow fault, electrical circuit fault, or an incomplete monitor.
intermediateUse lamp behavior, symptoms, code status, freeze frame, readiness, and system tests to understand what the vehicle detected without treating a code as a parts order.
beginnerReduced braking, unusually long stopping, or a vehicle that will not stop normally is a stop-driving condition. Secure the vehicle first, then separate hydraulic, assist, friction, mechanical, and control-system evidence with qualified service information.
professional recommendedA pedal that suddenly feels hard or requires much more effort can indicate loss of brake assist, a vacuum/electrical control concern, or another braking fault. Secure the vehicle and verify the exact assist system before driving or replacing parts.
professional recommendedTreat gasoline or diesel odor as a safety signal first, then separate a liquid leak, vapor-system concern, refueling spill, exhaust odor, and cabin-source issue without running the vehicle beside an active leak.
professional recommendedThe engine does not rotate when starting. Separate battery, cable, starter-control, interlock, security, and starter faults before replacing anything.
intermediateSeparate airflow, control, compressor-command, heat-rejection, refrigerant-circuit, and electrical concerns without venting refrigerant or guessing a charge.
professional recommendedSeparate battery state, mechanical drive, cable loss, alternator output, sensing, control strategy, and vehicle-load concerns before replacing the alternator.
intermediateUse the timing, affected circuits, electrical load, and vehicle state to separate a charging, connection, control, or individual lighting fault.
intermediateA soft, spongy, low, or sinking pedal can reflect hydraulic leakage or air, master-cylinder or control faults, mechanical adjustment or flex, and other foundation-brake concerns. Braking safety comes before diagnosis.
professional recommendedA partial vehicle hub with sourced identity, manufacturer-stated model-range engine and drivetrain configuration facts, and bounded maintenance/specification records; exact VIN applicability and unresolved configuration fields remain explicit.
Partial vehicle hubA partial vehicle hub with government-sourced identity and manufacturer-stated model-range powertrain facts; exact VIN engine, trim, drivetrain, repair, and specification applicability remain unpublished.
Partial vehicle hubSupports coolant circulation. Leaks, drive condition, flow, and engine design affect diagnosis.
General knowledgeRegulates coolant flow by temperature. Slow warm-up and overheating require different evidence.
General knowledgeTransfers coolant heat to airflow. External blockage, internal restriction, leakage, and fan behavior matter.
General knowledgeCoolant chemistry, concentration, capacity, fill, and bleed procedure vary by vehicle.
Verify vehicle intervalIAR does not passively record this search. Save feedback only if you want a local note that you can export later for editorial planning. VIN-like vehicle identifiers are redacted before local save.