Loading IAR content
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.
Select a vehicle when you want more relevant guidance. AI guidance stays separate from verified IAR source records.
Use 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.
beginnerSeparate a missing lamp or changed circuit load from socket, wiring, switch, module, hazard, and control evidence before replacing a flasher or lamp.
beginnerSeparate blade and glass conditions from fuse, switch, motor, linkage, washer, wiring, module, and frozen-system evidence while protecting visibility and the windshield.
intermediateRestore a safe rear-visibility workflow by separating a camera, reverse-input, power, ground, connector, display, network, or software concern before replacing a module.
intermediateThe engine does not rotate when starting. Separate battery, cable, starter-control, interlock, security, and starter faults before replacing anything.
intermediateSeparate actual low tire pressure from a TPMS malfunction, sensor, compatibility, registration, or relearn concern.
intermediateUse the first starting split—cranks or does not crank—to choose the correct electrical, authorization, fuel, ignition, or mechanical diagnostic path.
beginnerUse operating conditions, code context, cylinder patterns, and targeted tests to separate ignition, fuel, air, mechanical, and control causes.
intermediateUse the timing, affected circuits, electrical load, and vehicle state to separate a charging, connection, control, or individual lighting fault.
intermediateSeparate a failed lamp or local connection from fuse, ground, wiring, control, and configuration concerns before replacing parts.
beginnerSeparate true transmission slip or shift flare from engine power loss, traction-control intervention, clutch concerns, and normal ratio changes before condemning a transmission.
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.
intermediateReduced 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 recommendedSeparate fuel, spark, compression, timing, and security-system faults with a test-first process.
IntermediateElectrical diagnosis follows the circuit and the evidence. A module-related code can be caused by supply, ground, wiring, communication, input, output, configuration, or the module itself.
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 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 guideThe 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 guideThe control module reported a vehicle-speed-signal condition. The standardized code identifies the monitored speed-signal category; it does not prove which sensor, wheel-speed source, wiring path, module, or communication path is responsible.
Generic codeThe control module reported vehicle-speed-signal behavior outside its expected relationship. The standardized code identifies the monitored speed-signal category; it does not prove which sensor, wheel-speed source, wiring path, module, or communication path is responsible.
Generic codeThe control module detected a vehicle-speed-signal input below the range expected by its monitoring strategy. The generic code does not prove which sensor, wheel-speed source, wiring path, module, or communication path is responsible.
Generic codeThe control module detected intermittent, implausible, or high vehicle-speed-signal behavior. The generic code does not prove which sensor, wheel-speed source, wiring path, module, or communication path is responsible.
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 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 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 control module detected intake-air-temperature sensor behavior outside its expected range or relationship. The code does not by itself prove the sensor, wiring, connector, intake condition, or control module is the cause.
Generic codeThe control module detected an intake-air-temperature sensor signal in a low range for its monitoring strategy. The code does not by itself prove the sensor, wiring, connector, intake condition, or control module is the cause.
Generic codeThe control module detected an intake-air-temperature sensor signal in a high range for its monitoring strategy. The code does not by itself prove the sensor, wiring, connector, intake condition, or control module is the cause.
Generic codeThe control module detected a malfunction in the mass-or-volume-air-flow circuit. The code does not by itself identify the sensor, wiring, intake path, power/ground, or control module as the cause.
Generic codeThe control module detected a mass-or-volume-air-flow circuit signal in a low range for its monitoring strategy. The code does not by itself prove a MAF sensor, wiring, connector, intake path, power/ground, or control module is the cause.
Generic codeThe control module detected a mass-or-volume-air-flow circuit signal in a high range for its monitoring strategy. The code does not by itself prove a MAF sensor, wiring, connector, intake path, power/ground, or control module is the cause.
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 EVAP vent-control circuit. It does not identify the exact location of the short or prove the vent device itself is the cause.
Generic codeSeparate missing ignition, fuel delivery, control, synchronization, and mechanical evidence after the engine is confirmed to crank.
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 procedureUse warning behavior, scan context, cylinder pattern, and controlled contribution evidence to separate ignition, fuel, air, and mechanical branches.
Test-first procedureThe 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 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 promptlyIAR 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.