Deep Technical Diagnostic Atlas
A measurement-led atlas for electrical, network, engine, emissions, driveline, hydraulic, heavy-duty, EV and ADAS systems before parts replacement.
rail pressure command/actual, low-side supply, injector leak-off, regulator control
→AFTERTREATMENTDPF Differential Pressuredifferential pressure, soot estimate, ash loading, regeneration conditions
→AFTERTREATMENTSCR / DEF DosingDEF quality, dosing command, NOx upstream/downstream, catalyst temperature
→AIREGR Flow Controlcommanded EGR, measured airflow, manifold pressure, valve position
→AIRTurbo Boost Controlboost target/actual, actuator command, charge-air leaks, exhaust drive energy
→AIRVGT Actuatorvane command/feedback, soot binding, vacuum/electric drive, boost response
→AIRMAF Diagnosticsair mass, plausibility, intake leaks, EGR interaction
→AIRMAP / Boost Sensorkey-on plausibility, atmospheric reference, boost response, wiring
→EMISSIONSLambda / O2 Controlsensor response, heater circuit, fuel trims, catalyst context
→AFTERTREATMENTNOx Sensor Systemsensor supply, temperature readiness, upstream/downstream plausibility, SCR conversion
→AFTERTREATMENTEGT Sensor Chaintemperature gradient, cold-soak plausibility, wiring, regeneration context
→ENGINEElectronic Throttle Actuatorcommand/position correlation, motor current, deposits, supply/ground
→FUELInjector Balancecorrection values, cylinder contribution, leak-off, rail stability
→FUELHigh-Pressure Pumpsupply pressure, metering command, rail rise rate, contamination
→FUELLow-Pressure Fuel Supplypump command, voltage drop, pressure/flow, restriction
→ENGINEMisfire Analysismisfire counters, ignition/injection, compression, air leak
→MECHANICALCompression and Leak-downrelative compression, mechanical timing, leakage path, cylinder comparison
→TIMINGCam / Crank Correlationsync pattern, mechanical timing, VVT command, sensor integrity
→TIMINGVariable Valve Timingoil condition, target/actual angle, solenoid command, phaser response
→LUBRICATIONOil Pressure Controlmechanical pressure, commanded stage, oil temperature, pickup/filter condition
→THERMALCooling / Overheat Diagnosticscoolant temperature, thermostat behavior, fan command, flow/pressure
→ELECTRICAL12/24 V Charging Systemresting voltage, charging command, voltage drop, current demand
→ELECTRICALParasitic Draw / Sleepsleep transition, module wakeups, current trend, network activity
→ELECTRICALStarter and Crankingcranking voltage, current, rpm, voltage drop
→ELECTRICALGround Voltage Droploaded ground drop, shared grounds, connector heat, reference offsets
→NETWORKCAN Bus Diagnosticstermination resistance, bias levels, waveform, module isolation
→NETWORKLIN Bus Diagnosticsmaster wakeup, supply, line waveform, slave isolation
→NETWORKUDS Diagnostic SessionsDTC status, freeze-frame, session/security context, routine results
→NETWORKJ1939 Network DiagnosticsSPN/FMI, source address, bus integrity, active/inactive faults
→TRANSMISSIONAutomatic Transmission Diagnosticsfluid temperature, ratio error, clutch slip, pressure commands
→TRANSMISSIONDCT / Mechatronicsclutch adaptation, actuator position, hydraulic pressure, temperature
→TRANSMISSIONCVT Diagnosticsratio command/actual, pressure, temperature, pulley/belt behavior
→TRANSMISSIONHeavy-Duty Powershiftclutch pressure, speed sensors, calibration, oil temperature
→TRANSMISSIONTorque Converterlockup command/slip, temperature, engine/transmission speed
→DRIVELINETransfer Caserange command, actuator position, speed correlation, oil condition
→DRIVELINEDifferential Locklock command, position feedback, wheel speed context, pneumatic/electric actuation
→CHASSISABS Wheel Speed Sensorswheel speed correlation, air gap/tone ring, wiring, bearing play
→CHASSISESC Yaw / Steering Anglesteering angle, yaw/lateral acceleration, calibration, wheel speed
→CHASSISAir Suspensionride height, reservoir pressure, compressor duty, valve block leakage
→CHASSISTPMS Systemsensor identity, pressure/temperature, relearn state, RF reception
→HYDRAULICHydraulic Pump Diagnosticsstandby/load pressure, case drain, oil temperature, cavitation
→HYDRAULICHydraulic Valve / Spoolcommand current, spool response, pressure drop, contamination
→HYDRAULICLoad-Sensing HydraulicsLS signal, pump margin, compensator response, leakage
→HEAVYPTO Systemengagement command, interlocks, speed feedback, hydraulic/pneumatic actuation
→AGRITractor Three-Point Hitchposition/draft feedback, valve command, calibration, hydraulic pressure
→AGRITractor CVT / IVTrequested/actual ratio, hydrostatic branch, clutch states, calibration
→HEAVYAftertreatment Derateactive SPN/FMI, inducement stage, DEF/SCR/DPF state, engine protection
→HEAVYAir Brake Systemreservoir pressure, compressor, dryer, modulator command, leaks
→HEAVYRetarder / Intardercommanded braking, temperature, CAN request, speed/gear context
→BUSBus Door Pneumaticsair pressure, interlocks, position sensors, valve command
→OFFHIGHWAYConstruction Machine Regenerationsoot load, exhaust temperature, inhibit state, engine load
→OFFHIGHWAYExcavator Swing Systempilot pressure, command, motor case drain, brake release
→OFFHIGHWAYLoader Hydraulic Powerpump pressure, implement command, lift/tilt cylinder leakage, temperature
→ADASADAS Camera Calibrationmounting geometry, calibration status, DTCs, target/road procedure prerequisites
→ADASRadar Calibrationmounting angle, bracket damage, calibration state, alignment prerequisites
→EVEV High-Voltage Isolationisolation status, contactor state, moisture/connector context, safe service procedure
→EVEV Battery / BMScell voltage spread, temperature, SOC/SOH context, contactor/precharge state
→EVInverter / Traction MotorDC bus, phase current, resolver position, thermal limits
→EVOn-Board ChargerAC input, pilot state, DC output, thermal/network status
→EVDC Fast Charginghandshake state, pack limits, connector temperature, charger/vehicle fault ownership
→HYBRIDHybrid Energy Flowengine/motor torque request, SOC, clutch states, regen limits
→MARINEMarine Engine Coolingraw-water flow, impeller, heat exchanger, exhaust temperature
→MARINEMarine Fuel Systemwater contamination, lift pressure, filters, rail/carburetion context
→STATIONARYGenerator Governor / Frequencyengine speed, load step response, actuator command, frequency stability
→Sources & freshness
Exact technical values, prices and failure rates are not invented without verified vehicle/manufacturer evidence.