Auto Diagnosis Test #7 Review Your own hand written notes may be used for the 1 st 10 minutes of the test Based on Chapters 25, 26, 32, 33, 34 and Lab Demonstrations
Auto Diagnosis Test #7 Review Your own hand written notes may be used for the 1 st 10 minutes of the test For the Most Effective Personal Review, Look Over the On Line Study Guide Multimedia
Chapter 25 Information #2 Air & Fuel & Heat #5 Timing the Fuel & Heat Delivery
Chapter 25 Information #14 Stoichiometric for Gasoline #15 Lean is more air than stoichiometric #16 Rich is less air than stoichiometric
Chapter 25 Information #17 Emission Controls why? #19 HC definition & causes No Burn or EVAP #20 CO definition & causes Burning Too Rich #21 NOx definition & causes Burning Too Hot
Chapter 25 Information #24 Sensors #32 36 OBD II Basics: DLC, DTC, MIL, etc. #38 Loops #39 Closed Loop #40 Open Loop
Chapter 25 Information #41 Fail Safe or Limp in #42 Adaptive Strategy & Readiness Monitors #44 Continuous Monitors #45 Non continuous Monitors
Chapter 25 Information #50 Oxygen Sensors #51 Misfire Monitor #62 Comprehensive Component Monitor #64 DTC s and the MIL
Chapter 26 Information #1 Sensors are Inputs #2 DTC s & the MIL #4 More than 1 cause for a DTC is possible #5 Monitors must be run to set a DTC #7 Misfire Monitor Freeze Frame Once per Trip Flags Continuously Monitored No Flags Comprehensive Component Monitor Misfire (counter & cylinder ID) Fuel Trim (STFT & LTFT) Catalytic Converter O2 Sensor O2 Heater EGR AIR EVAP
Chapter 26 Information #9 Symptom Based Diagnostics #11 What Sensors Actually Sense #12 & 13 Lab Scope Use #18 Switches as Sensors!
Chapter 26 Information #19 Thermistors as Sensors (ECT & IAT & TFT) #20 Pressure Sensors (piezo resistive) #23 MAF Sensor is a wheatstone bridge #25 Normal MAF is 4 7 gm/sec #26 #32 Oxygen Sensors!! Zirconic vs. Titanium #33 TPS & APP are Potentiometers #37 CKP & CMP are often Hall effect sensors #39 Knock Sensor (piezo generator)
Chapter 26 Information #40 Actuators & what they do Outputs controlled by the PCM include devices such as: Solenoids Relays Motors Lights Diagnostics (DTCs) These components control the operation of systems such as: A/C Compressor Clutch AIR Cruise Control MIL EVAP EGR Idle Air Control Cooling Fan Diagnostics (DTCs) Engine Torque Mgmt Fuel Pump Fuel Injector(s) Ignition Control Manifold Tuning Shift Light Throttle Control Torque Converter Clutch Transmission Shift Transmission Pressure
Chapter 32 Information #3 Definition of Vacuum #6 Normal Engine Vacuum Readings #9 14 Intake manifolds & variations
Chapter 32 Information #20 Super charging & Turbo charging #25 Turbo lag #26 Waste Gate #37 Super charger clutch
Chapter 32 Information #46 50 Catalytic Converters #53 Exhaust Back Pressure
Chapter 33 Information #2 HC #3 CO #4 NOx #9 Water in the exhaust is normal! HC CO NOx Unburned fuel All petroleum products Produced by incomplete combustion or fuel evaporation Extremely toxic Colorless and odorless Prevents blood cells from carrying oxygen to body tissues Caused by rich air fuel mixtures Air consists of 79% nitrogen and 21% oxygen Above approximately 2500 ºF, 1370 ºC, nitrogen and oxygen combine Caused by high compression ratio, lean burning, high operating temps
Chapter 33 Information #14 The Chart Initials Full Name Type Pollutants Lowered TAC Thermostatic Air Cleaner pre combustion HC CO NOx EGR Exhaust Gas Recirculation pre combustion HC CO NOx EVAP Evaporative System evaporative HC CO NOx EFE Early Fuel Evaporation pre combustion HC CO NOx ~~~~~~ CAT Catalytic Converter post combustion HC CO NOx AIR Air Injection System post combustion HC CO NOx PCV Positive Crankcase Ventilation post combustion HC CO NOx
Chapter 33 Information #15 18 EVAP System Canister #21 24 PCV System PCV Valve #25 29 EGR System EGR Valve
Chapter 33 Information #30 EFE was used on Carburetors & TBI #32 34 Catalytic Converter Operation/Theory
Chapter 33 Information #35 37 Secondary Air Systems
Chapter 33 Information #38 43 Clean Diesels, Common Rail Injection #44 48 Diesel Exhaust After Treatment
Chapter 33 Information #38 43 Clean Diesels, Common Rail Injection #44 48 Diesel Exhaust After Treatment
Chapter 34 Information #1 Engine efficiency & pollution #2 There will always be some exhaust pollution #3 Common Exhaust Pollutants
Chapter 34 Information #4 5 IM 240 Testing under load #6 Cut points
Chapter 34 Information #9 Stoichiometric = Lambda #10 Before Diagnosis #11 Continuous & Non Continuous Monitors Readiness Monitors are Computer Self Tests that will Generate DTC s for Failures
Chapter 34 Information #11 Continuous & Non Continuous Monitors Readiness Monitors must be completed & passed in order to pass a DMV Emission Test!!
Chapter 34 Information #12 15 EVAP Testing #16 23 PCV Testing
Chapter 34 Information #24 27 EGR Testing Bi Directional or Activation Tests Using the Scan Tool
Chapter 34 Information #28 32 Catalytic Converter Testing
Chapter 34 Information #33 35 AIR (Secondary Air) Testing Bi Directional or Activation Tests Using the Scan Tool
Great Stuff To Know Throttle Actuator Motor Accelerator Pedal Position Sensor Throttle by Wire System
Great Stuff To Know Throttle by Wire
Great Stuff To Know Using TSB s to save time in diagnosis Why does a CAT get hotter? (chemical reaction!) PID is a Parameter Identifier (abbreviation) Quad Driver = Huge Switching Transistor
Know Your Sensors!!
Know Your Definitions!!
Know Your Pollutants!!
Know Your Emission Controls!! CAT, AIR, PCV, TAC, EVAP, EGR, EFE
Catalytic Converter Remedy/Post Combustion HC, CO, NOx
AIR Injection or Secondary Air System Remedy/Post Combustion HC & CO
Positive Crankcase Ventilation Remedy/Post Combustion HC & CO
Thermostatic Air Cleaner Pre Combustion Control HC & CO Goal is 80º to 120º Incoming Air Temp
Evaporative System Fuel Evaporation Control HC
Exhaust Gas Recirculation Pre Combustion Control (cools the burn) NOx
Early Fuel Evaporation Pre Combustion HC & CO Carburetor & TBI
Electronic Engine Control System Block Diagram
ABS Chassis SRS HVAC Anti Theft Body Scan Tool Sensors Inputs PCM DLC HO2S MIL TPS ECT Engine Outputs Actuators Ignition Spark IAT MAF MAP CKP CMP Open Loop Mode Closed Loop Mode Clear Flood Mode Limp In Mode EFI Emission Controls Cruise Accessories P/N KS VSS Electronic Engine Control System Block Diagram
Sensors Upstream (A/F) & Downstream (CAT) HO2S TPS ECT IAT MAF MAP CKP CMP P/N ABS Chassis Inputs SRS HVAC Anti Theft PCM PROM & RAM Engine Open Loop Mode Closed Loop Mode Clear Flood Mode Limp In Mode Outputs Body DLC MIL Actuators Ignition Spark EFI (injectors & IAC) Emission Controls (6) CAT AIR PCV TAC EVAP EGR Cruise Scan Tool DTC s Accessories Instrument Cluster KS VSS Electronic Engine Control System Block Diagram