Engine Controls - System/Component Tests

• Model Identification
• Introduction
• Air Induction Systems
  • Turbocharger (4.3L PFI)
    • Notes
    • Charge Air Cooler Pump
    • Wastegate Diaphragm
    • Wastegate Solenoid
• Computerized Engine Controls
  • Control Unit
    • Notes
    • Ground Circuits
    • Power Circuits
    • Quad-Driver Check (Except 3.1L & 4.3L Turbo)
• Engine Sensors & Switches
  • A/C On Switch/System Test
  • Brake Switch
  • Coolant Temperature Sensor (Cts)
  • Knock Sensor
  • Manifold Absolute Pressure (Map) Sensor
  • Manifold Air Temperature (Mat) Sensor
  • Oxygen (O2) Sensor
  • Oxygen Sensor Heating Element (4.3L Turbo PFI)
  • Park/Neutral (P/N) Switch
  • Power Steering Pressure Switch (2.5L)
  • Throttle Position Sensor (TPS)
  • Vehicle Speed Sensor (Pm Generator)
• Relays, Solenoids, Motors & Modules
  • Relays
    • A/C Relays
    • Cold Advance Relay (6.2L Diesel)
    • Fuel Pump Relay
  • Solenoids
    • Notes
    • Canister Purge Solenoid
    • Electronic Air Control (EAC) Solenoid
    • EGR Control Solenoid
    • Torque Converter Clutch (TCC) Solenoid
    • Wastegate Solenoid (4.3L Turbo PFI)
  • Motors
    • Charge Air Cooler Pump (4.3L Turbo)
    • Idle Air Control (IAC) Motor
• Fuel System (Gasoline)
  • Fuel Delivery
    • Notes
    • Fuel Pressure Regulator (PFI)
    • Fuel Pressure Regulator (TBI)
    • Fuel Pump Oil Pressure Switch (Back-Up Circuit)
    • Fuel Pump Relay
    • Fuel Pump Relay By-Pass Procedure
  • Fuel Control
    • Fuel Injector(s)
    • Oxygen Sensor
    • PFI Injector Balance Test (C-2)
  • Idle Control System
    • Idle Air Control (IAC) Motor
• Idle Air Control - Vehicles Without 4L80-E Transmission
  • Description
  • Test Description
  • IAC Valve Reset Procedure
  • Idle Air Control System Check Chart
    • Notes
    • Diagnostic Aids
    • Vacuum Leak (High Idle)
    • System Too Rich (Low Air/Fuel Ratio)
    • Throttle Body
    • IAC Valve Electrical Connections
    • PCV Valve
    • A/C Compressor Or Relay Failure
• Fuel System (Diesel)
  • Notes
  • Normal Glow Plug Circuit Operation
  • Preliminary Glow Plug Diagnosis
  • Inhibit Switch (Black Cap)
  • Glow Plug System Diagnosis
    • Electrical Check
  • No Start - Cold
  • Diesel Cold Advance System Check
    • Notes
    • Cold Advance Relay
  • Glow Plug Controller
  • Injection Pump Housing Leakage Test
  • Injectors
    • Test Preparation
    • Opening Pressure Test
    • Leakage Test
    • Chatter Test
    • Spray Pattern Test
• Ignition System
  • Notes
  • Timing Control Systems (C-4 & C-5)
    • C-4, Electronic Spark Timing (Gasoline Engines)
    • C-5, Electronic Spark Control (ESC) Circuit (Gas Engines Except 2.5L, 4.3L Turbo & Vehicles With 4L80-E Transmission)
    • C-5, Electronic Spark Control (ESC) Circuit (4.3L Turbo & Vehicles With 4L80-E Transmission)
• Emission Systems & Sub-Systems (Gasoline)
  • Air Injection (C-6)
    • Air Pump
    • Check Valve
    • Electronic Air Control (EAC) Solenoid
  • Exhaust Gas RECIRCULATION (C-7)
    • System Test
    • EGR Control Solenoid
    • Negative Backpressure EGR Valve
    • Linear EGR Valve (4.3L CPI)
  • Fuel Evaporation Control (C-3)
    • Vapor Canister Purge Valve ("P" Series & 4.3L CPI)
    • Fuel Tank Pressure Control Valve (C, G, K & M Series-High-Altitude)
    • Thermostatic Vacuum Switch
  • Positive Crankcase Ventilation
    • Required Service
    • A leaking PCV valve or hose could cause:
    • Checking PCV Valve Function (Except 2.5L)
  • Thermostatic Air Cleaner
    • Temperature Sensor Vacuum Motor Type (2.8L)
    • Vacuum Motor Diaphragm (2.8L)
    • Damper Door Wax Pellet Check (Except 2.8L)
• Emission Systems & Sub-Systems (Diesel)
  • Positive Crankcase Ventilation
    • Crankcase Depression Regulator (CDR)
  • Exhaust Gas RECIRCULATION (EGR)
    • EGR Valve Check
  • Exhaust Pressure Regulation (EPR) System
  • Vacuum Pump
• Miscellaneous ECM Controls
  • Notes
  • Transmission (C-8)
    • Torque Converter Clutch (TCC) Solenoid
    • Converter Lock-Up Signal At Transmission
    • Converter Lock-Up Signal From ECM
    • Shift Light (Manual Transmission)
  • A/C Clutch (C-10) & Electric Cooling Fan (C-12)
  • A/C Clutch (C-10)
    • A/C Clutch Relay
  • Cooling Fan (C-12)
    • Notes
    • Cooling Fan Relay
    • Cooling Fan Motor
  • CHART C-10, A/C CLUTCH CONTROL CKT DIAGNOSIS 2.5/2.8L (1 Of 2)
  • CHART C-10, A/C CLUTCH CONTROL CKT DIAGNOSIS 2.5/2.8L (2 Of 2)
    • Notes
    • Diagnostic Aids
  • CHART C-10, A/C CLUTCH CONTROL CIRCUIT DIAGNOSIS (FRONT A/C ONLY) 3.1L (1 of 2)
    • Notes
    • Diagnostic Aids
  • Chart C-10, A/C Clutch Control Circuit Diagnosis (Rear A/C Only) (2 Of 2) 3.1L
    • Notes
    • Diagnostic Aids
  • Chart C-10, A/C Control Diagnosis (A/T) (1 Of 2) 4.3L Turbo PFI
  • Chart C-10, A/C Clutch Control Diagnosis (A/T) (2 Of 2) 4.3L Turbo PFI
    • Notes
    • Diagnostic Aids
  • Chart C-12, Cooling Fan Circuit Diagnosis (1 Of 2) 3.1L
    • Notes
    • Diagnostic Aids
  • Chart C-12, Cooling Fan Circuit Diagnosis (2 Of 2) 3.1L
  • Chart C-12A, Cooling Fan Circuit Diagnosis (1 Of 4) 3.8L
    • Notes
    • Diagnostic Aids
  • Chart C-12B, Cooling Fan, On At All Times (2 Of 4) 3.8L
  • Chart C-12C, Cooling Fan, No Puller Fan (3 Of 4) 3.8L
  • Chart C-12D, Cooling Fan, No Pusher Fan (4 Of 4) 3.8L
• Intake Manifold Tuning Valve Assembly
  • Description & Operation
  • Removal & Installation
    • Removal
    • Installation
  • Diagnostic Aids
• Component Locations