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Electronic Engine and Emission Controls Service

AGM 142

Electronic Engine and Emission Controls Service

AGM 142

Course Description

Prerequisite: AGM 112. Introduces the operation, maintenance, and service of GM engines for drivability performance. Stresses proper repair techniques and diagnosis of engine drivability problems. Credit may be earned in AGM 142 or SKGM 142 or ACD 142 but not in more than one. (81-144)

Outcomes and Objectives

Diagnose engine performance. Complete 95% of Priority 1, 80% of Priority 2, and 50% of Priority 3 NATEF tasks as listed below.

Objectives:

  • Identify and interpret engine performance concern; determine necessary action. P-1
  • Research applicable vehicle and service information, such as engine management system operation, vehicle service history, service precautions, and technical service bulletins. P-1
  • Locate and interpret vehicle and major component identification numbers (VIN, vehicle certification labels, and calibration decals). P-1
  • Diagnose abnormal exhaust color, odor, and sound; determine necessary action. P-2
  • Perform engine absolute (vacuum/boost) manifold pressure tests; determine necessary action. P-1
  • Perform cylinder power balance test; determine necessary action. P-1
  • Perform cylinder compression tests; determine necessary action. P-1
  • Perform cylinder leakage test; determine necessary action. P-1
  • Diagnose engine mechanical, electrical, electronic, fuel, and ignition concerns with an oscilloscope and/or engine diagnostic equipment; determine necessary action. P-1
  • Verify engine operating temperature; determine necessary action. P-1
  • Perform cooling system pressure tests; check coolant condition; inspect and test radiator, pressure cap, coolant recovery tank, and hoses; perform necessary action. P-1
  • Verify correct camshaft timing. P-2

Diagnose and repair emissions control systems--evaporative emissions controls. Complete 95% of Priority 1, 80% of Priority 2, and 50% of Priority 3 NATEF tasks as listed below.

Objectives:

  • Inspect and test components and hoses of evaporative emissions control system; perform necessary action. P-1
  • Inspect and test components and hoses of evaporative emissions control system; perform necessary action. P-1

Diagnose and repair engine related service. Complete 95% of Priority 1, 80% of Priority 2, and 50% of Priority 3 NATEF tasks as listed below.

Objectives:

  • Adjust valves on engines with mechanical or hydraulic lifters. P-1
  • Remove and replace timing belt; verify correct camshaft timing. P-1
  • Remove and replace thermostat. P-2
  • Inspect and test mechanical/electrical fans, fan clutch, fan shroud/ducting, air dams, and fan control devices; perform necessary action. P-1

Diagnose and repair computerized engine controls. Complete 95% of Priority 1, 80% of Priority 2, and 50% of Priority 3 NATEF tasks as listed below.

Objectives:

  • Retrieve and record stored OBD I diagnostic trouble codes; clear codes. P-2
  • Retrieve and record stored OBD II diagnostic trouble codes; clear codes. P-1
  • Diagnose the causes of emissions or driveability concerns resulting from malfunctions in the computerized engine control system with stored diagnostic trouble codes. P-1
  • Diagnose the causes of emissions or driveability concerns resulting from malfunctions in the computerized engine control system with stored diagnostic trouble codes. P-1
  • Check for module communication errors using a scan tool. P-2
  • Inspect and test computerized engine control system sensors, powertrain control module (PCM), actuators, and circuits using a graphing multimeter (GMM)/digital storage oscilloscope (DSO); perform necessary action. P-1
  • Obtain and interpret scan tool data. P-1
  • Access and use service information to perform step-by-step diagnosis. P-1

Diagnose and repair ignition system. Complete 95% of Priority 1, 80% of Priority 2, and 50% of Priority 3 NATEF tasks as listed below.

Objectives:

  • Diagnose ignition system related problems such as no-starting, hard starting, engine misfire, poor driveability, spark knock, power loss, poor mileage, and emissions concerns on vehicles with electronic ignition (distributorless) systems; determine necessary action. P-1
  • Diagnose ignition system related problems such as no-starting, hard starting, engine misfire, poor driveability, spark knock, power loss, poor mileage, and emissions concerns on vehicles with distributor ignition (DI) systems; determine necessary action. P-1
  • Inspect and test ignition primary circuit wiring and solid state components; perform necessary action. P-2
  • Inspect, test and service distributor. P-3
  • Inspect and test ignition system secondary circuit wiring and components; perform necessary action. P-2
  • Inspect and test ignition coil(s); perform necessary action. P-1
  • Check and adjust ignition system timing and timing advance/retard (where applicable). P-3
  • Inspect and test ignition system pick-up sensor or triggering devices; perform necessary action. P-1

Diagnose and repair fuel, air induction, and exhaust systems. Complete 95% of Priority 1, 80% of Priority 2, and 50% of Priority 3 NATEF tasks as listed below.

Objectives:

  • Check fuel for contaminants and quality; determine necessary action. P-3
  • Inspect and test mechanical and electrical fuel pumps and pump control systems for pressure, regulation and volume; perform necessary action. P-1
  • Inspect throttle body, air induction system, intake manifold and gaskets for vacuum leaks and/or unmetered air P-2
  • Inspect and test fuel injectors. P-2
  • Check idle speed and fuel mixture. P-2
  • Adjust idle speed and fuel mixture. P-3
  • Inspect the integrity of the exhaust manifold, exhaust pipes, muffler(s), catalytic converter(s), resonator(s), tail pipe(s), and heat shield(s); perform necessary action. P-2
  • Perform exhaust system back-pressure test; determine necessary action. P-1

Diagnose and repair emissions control systems--positive crankcase ventilation. Complete 95% of Priority 1, 80% of Priority 2, and 50% of Priority 3 NATEF tasks as listed below.

Objectives:

  • Diagnose oil leaks, emissions, and driveability problems resulting from malfunctions in the positive crankcase ventilation (PCV) system; determine necessary action. P-2
  • Inspect, test and service positive crankcase ventilation (PCV) filter/breather cap, valve, tubes, orifices, and hoses; perform necessary action. P-2

Diagnose and repair emissions control systems--exhaust gas recirculation. Complete 95% of Priority 1, 80% of Priority 2, and 50% of Priority 3 NATEF tasks as listed below.

Objectives:

  • Diagnose emissions and driveability problems caused by malfunctions in the exhaust gas recirculation (EGR) system; determine necessary action. P-1
  • Inspect, test, service and replace components of the EGR system, including EGR tubing, exhaust passages, vacuum/pressure controls, filters and hoses; perform necessary action. P-2
  • Inspect and test electrical/electronic sensors, controls, and wiring of exhaust gas recirculation (EGR) systems; perform necessary action. P-2

Diagnose and repair emissions control systems--exhaust gas treatment. Complete 95% of Priority 1, 80% of Priority 2, and 50% of Priority 3 NATEF tasks as listed below.

Objectives:

  • Inspect and test catalytic converter performance. P-1

Diagnose and repair emissions control systems--intake air temperature controls. Complete 95% of Priority 1, 80% of Priority 2, and 50% of Priority 3 NATEF tasks as listed below.

Objectives:

  • Diagnose emissions and driveability problems resulting from malfunctions in the intake air temperature control system; determine necessary action. P-3
  • Inspect and test components of intake air temperature control system; perform necessary action. P-3

Diagnose and repair emissions control systems--early fuel evaporation (intake manifold temperature) controls. Complete 95% of Priority 1, 80% of Priority 2, and 50% of Priority 3 NATEF tasks as listed below.

Objectives:

  • Diagnose emissions and driveability problems resulting from malfunctions in the early fuel evaporation control system; determine necessary action. P-3