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Engine Controls - Trouble Shooting - No Codes: Other Chevrolet Tracker II

Testing & Diagnostics ~4292 words

Possible Causes & Corrections

Check the following items

  1. Check coolant level. Check cooling system thermostat for proper operation and application.
  2. Check cooling fan for proper operation.
  3. Check for restricted airflow to radiator or restricted coolant flow through radiator.
  4. Check for loose water pump belt.
  5. Check Knock Sensor (KS) system for no retard.
  6. Remove spark plugs and check for correct heat range, wear, cracks, wetness, improper gap or heavy deposits.
  7. Check for incorrect mechanical engine parts such as camshaft, cylinder heads and pistons.
  8. Check for plugged PCV system.
  9. Check transmission shift pattern and downshift operation.
  10. Check Transaxle Range (TR) switch input with vehicle in drive and shifter in drive or overdrive.
  11. Check Torque Converter Clutch (TCC) for proper operation.
  12. Check Park Neutral Position (PNP) switch circuit. Ensure PNP switch is properly adjusted.
  13. Ensure initial timing is correct.
  14. Check PCM grounds. Ensure they are clean, tight and properly located.
  15. Remove carbon from engine with top engine cleaner.
  16. Check fuel system for incorrect fuel pressure. Perform BASIC FUEL SYSTEM CHECKS. See FUEL SYSTEMS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  17. Check for poor fuel quality and proper octane rating. If scan tool readings are normal and no engine mechanical faults are present, fill fuel tank with a premium fuel and re-evaluate vehicle performance.
  18. Check for a shifted Engine Coolant Temperature (ECT) sensor. See DIAGNOSTIC TESTS in appropriate SELF-DIAGNOSTICS article.
  19. If emission test shows excessive NOx emissions, check all systems and components which could cause engine to run lean or too hot.
  20. Check EGR operation.
  21. Ensure correct PROM is installed in vehicle. Check dealer for latest application.

Check the following items

  1. Ensure EGR valve is not stuck open.
  2. Check for engine vacuum leaks. Ensure engine is tuned to specifications.
  3. Using Spark Tester (J-26792), check available output voltage of ignition coil.
  4. Check air induction system for restrictions or air leaks.
  5. Check exhaust system for restrictions, such as a damaged or collapsed pipe, muffler or catalytic converter. See EXHAUST SYSTEM BACKPRESSURE under MECHANICAL INSPECTION in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  6. Check fuel injectors. Perform injector balance test. See FUEL INJECTOR BALANCE TEST under FUEL SYSTEMS in appropriate SYSTEM & COMPONENT TESTING article.
  7. Check fuel system for incorrect fuel pressure. See BASIC FUEL SYSTEM CHECKS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  8. Check engine compression. Check for incorrect valve timing, bent push rods, broken valve springs or worn camshaft lobes.
  9. Check transmission shift solenoid system and Torque Converter Clutch (TCC) system for proper operation.
  10. Check for intermittent ignition system problem.
  11. Check intake and exhaust manifold passages for casting flash.
  12. Remove spark plugs and check for wet plugs, cracks, improper gap, burned electrodes or heavy carbon deposits. Also, check condition of spark plug wires. Spray spark plug wires with a fine mist of water to check for shorts.
  13. Ensure initial ignition timing is properly set.
  14. Ensure speedometer is properly calibrated.

Check the following items

  1. Check for restricted exhaust system. See EXHAUST SYSTEM BACKPRESSURE under MECHANICAL INSPECTION in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  2. Check engine compression. Check for incorrect valve timing, bent push rods, broken valve springs or worn camshaft lobes.
  3. Using Spark Tester (J-26792), check for adequate spark at spark plugs.
  4. Check ignition system for faulty ground and power feed circuits.
  5. Check for proper Crankshaft Position (CKP) and Camshaft Position (CMP) sensor resistance.
  6. Remove spark plugs and check for wet plugs, cracks, improper gap, burned electrodes or heavy carbon deposits. Also, check condition of spark plug wires. Spray spark plug wires with a fine mist of water to check for shorts.
  7. Check Transaxle Range (TR) switch input with vehicle in drive and shifter in drive or overdrive.
  8. Check for poor quality or alcohol contaminated fuel.
  9. Check fuel injectors. Perform injector balance test. See FUEL INJECTOR BALANCE TEST under FUEL SYSTEMS in appropriate SYSTEM & COMPONENT TESTING article.
  10. Check fuel system for incorrect fuel pressure. See BASIC FUEL SYSTEM CHECKS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  11. Ensure EGR valve is not stuck open.
  12. Check air induction system for restrictions or air leaks.
  13. Check PCM grounds. Ensure they are clean, tight and properly located.
  14. Check TP sensor for sticking and binding. Check for correct TP sensor voltage. See FUEL SYSTEMS in appropriate SERVICE & ADJUSTMENT SPECIFICATIONS article.
  15. Check PCV system for proper operation.

Check for the following

  1. Check PCM grounds. Ensure they are clean, tight and properly located.
  2. Check for poor quality or alcohol contaminated fuel.
  3. Check canister purge system (staying on).
  4. Check for fuel in pressure regulator vacuum hose. If fuel is present, replace regulator.
  5. Check fuel system for incorrect fuel pressure. See BASIC FUEL SYSTEM CHECKS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  6. Check fuel injectors. Perform injector balance test. See FUEL INJECTOR BALANCE TEST under FUEL SYSTEMS in appropriate SYSTEM & COMPONENT TESTING article.
  7. Check injector harness locations. Ensure injectors are connected to correct injector/cylinder according to firing order.

Check the following items

  1. Check for lead contamination of catalytic converter. Check for removal/tampering at restrictor in fuel filler neck.
  2. Check for plugged PCV system.
  3. Check EGR operation.
  4. If emission test shows excessive CO and HC emissions and vehicle emits odor, check all systems and components which could cause engine to run rich.
  5. If emission test shows excessive NOx emissions, check all systems and components which could cause engine to run lean or too hot.

Check the following items

  1. Check exhaust system for restrictions, such as a damaged or collapsed pipe, muffler or catalytic converter. See EXHAUST SYSTEM BACKPRESSURE under MECHANICAL INSPECTION in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  2. Check ignition system for bare or shorted spark plug wires, loose ignition coil connections. Check for shorts by misting plug wires with water.
  3. Check ignition system for faulty grounds.
  4. Using Spark Tester (J-26792), check for adequate spark output.
  5. Remove spark plugs. Check for wet/fouled spark plugs, cracks in porcelain, improper gap, burned electrodes or heavy carbon deposits.
  6. Check fuel pump relay. Connect test light between fuel pump test terminal and ground. Turn ignition on. Test light should illuminate for 2 seconds. If test light does not illuminate, check fuel pump relay. For location of fuel pump relay and test connector, see appropriate SYSTEM & COMPONENT TESTING article.
  7. Check for poor fuel quality or alcohol/water-contaminated fuel.
  8. Check fuel system for incorrect fuel pressure. See BASIC FUEL SYSTEM CHECKS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  9. Check for plugged injectors. Perform injector balance test. See FUEL INJECTOR BALANCE TEST under FUEL SYSTEMS in appropriate SYSTEM & COMPONENT TESTING article.
  10. Check for faulty in-tank fuel pump check valve (if equipped). A faulty check valve allows fuel in lines to drain back to tank after engine is stopped.
  11. Check EGR operation.
  12. Ensure Engine Coolant Temperature (ECT) sensor circuit resistance is not too high. See appropriate SENSOR OPERATING RANGE CHARTS article.
  13. Ensure TP sensor does not stick or bind. A sticking throttle shaft or binding linkage may cause a high TP sensor voltage (open throttle indication). PCM will not control idle if high voltage is sensed.
  14. Check Idle Air Control (IAC) system. Check for vacuum leak at high idle. Check for binding of throttle blade or linkage. Check for foreign material in IAC bore of throttle body. Check for proper connection of IAC valve electrical connector.
  15. Check resistance of ECT and Intake Air Temperature (IAT) sensors. On a cold engine, ECT and IAT sensor readings should be within 5°F of each other.
  16. Ensure correct PROM and PCM are installed in vehicle. Check with dealer for latest application information.
  17. Check Manifold Absolute Pressure (MAP) or Mass Airflow (MAF) sensor. Check air intake tube for air leaks, blockage or damage.
  18. Inspect Crankshaft Position (CKP) sensor clearance and resistance Check harmonic balancer interrupter rings for bent or missing vanes.
  19. Check PCM and engine grounds for correct locations, tight and clean connections. See WIRING DIAGRAMS article.

Check for the following items

  1. Remove spark plugs and check for wet plugs, cracks, improper gap, burned electrodes or heavy carbon deposits. Also, check condition of spark plug wires. Spray spark plug wires with a fine mist of water to check for shorts.
  2. Check for open in ignition system ground circuit. Ensure initial ignition timing is correct.
  3. Check fuel system for incorrect fuel pressure. See BASIC FUEL SYSTEM CHECKS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  4. Check for plugged injectors. Perform injector balance test. See FUEL INJECTOR BALANCE TEST under FUEL SYSTEMS in appropriate SYSTEM & COMPONENT TESTING article.
  5. Check for poor fuel quality or water-contaminated fuel.
  6. Ensure TP sensor does not stick or bind. Voltage should increase at a steady rate as throttle is moved toward Wide Open Throttle (WOT).
  7. Check Manifold Absolute Pressure (MAP) sensor response and accuracy. See appropriate SYSTEM & COMPONENT TESTING article.
  8. Check canister purge system for proper operation.
  9. Check EGR valve for proper operation.
  10. Check exhaust system for restrictions, such as a damaged or collapsed pipe, muffler or catalytic converter. See EXHAUST SYSTEM BACKPRESSURE under MECHANICAL INSPECTION in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  11. Check Heated Oxygen Sensor (HO2S) for contamination. This will cause a false high voltage signal to PCM. PCM will respond by leaning out air/fuel ratio.
  12. Ensure correct PROM is installed in PCM. Check dealer for latest application.
  13. Check charging system output. Repair if output is less than 9 volts or greater than 16 volts.

Check the following items

  1. Check exhaust system for restrictions, such as a damaged or collapsed pipe, muffler or catalytic converter. See EXHAUST SYSTEM BACKPRESSURE under MECHANICAL INSPECTION in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  2. Check engine compression. Check for incorrect valve timing, bent push rods, broken valve springs or worn camshaft lobes.
  3. Check fuel injectors. Perform injector balance test. See FUEL INJECTOR BALANCE TEST under FUEL SYSTEMS in appropriate SYSTEM & COMPONENT TESTING article.
  4. Check fuel system for incorrect fuel pressure. See BASIC FUEL SYSTEM CHECKS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  5. Check transmission shift solenoid system and Torque Converter Clutch (TCC) system for proper operation.
  6. Using Spark Tester (J-26792), check for adequate spark output.
  7. Ensure correct initial ignition timing.
  8. Check Knock Sensor (KS) system for excessive retard.
  9. Check air filter and fuel filter. Replace if necessary.
  10. Check for poor fuel quality or water-contaminated fuel.
  11. Check fuel injector wires for short to ground at air cleaner.
  12. Check PCM grounds. Ensure they are clean, tight and properly located.
  13. Ensure EGR valve is not stuck open.
  14. Check charging system output. Repair if output is less than 9 volts or greater than 16 volts.
  15. Check A/C for proper operation.

Check the following items

  1. Check for a clogged air filter.
  2. Check air induction system for restrictions or air leaks.
  3. Check exhaust system for restrictions, such as a damaged or collapsed pipe, muffler or catalytic converter. See EXHAUST SYSTEM BACKPRESSURE under MECHANICAL INSPECTION in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  4. Check engine compression. Check for incorrect valve timing, bent push rods, broken valve springs or worn camshaft lobes.
  5. Check Park Neutral Position (PNP) switch circuit. Ensure PNP switch is properly adjusted.
  6. Check Torque Converter Clutch (TCC) system for proper operation.
  7. Check for dragging brakes.
  8. Check cooling system thermostat for proper heat range and operation.
  9. Remove spark plugs and check for wet/fouled spark plugs, cracks, improper gap, burned electrodes or heavy carbon deposits.
  10. Check fuel system for incorrect fuel pressure. See BASIC FUEL SYSTEM CHECKS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  11. Check fuel injectors. Perform injector balance test. See FUEL INJECTOR BALANCE TEST under FUEL SYSTEMS in appropriate SYSTEM & COMPONENT TESTING article.
  12. Check injector harness locations. Ensure injectors are connected to correct injector/cylinder according to firing order.
  13. Check Engine Coolant Temperature (ECT) sensor for shift in calibration. See appropriate SENSOR OPERATING RANGE CHARTS article.
  14. Check PCV system for proper operation.
  15. Check for proper Crankshaft Position (CKP) and Camshaft Position (CMP) sensor resistance.
  16. Check for fuel in pressure regulator vacuum hose. If fuel is present, replace regulator.
  17. Ensure speedometer is properly calibrated.
  18. Ensure A/C system is not always on.
  19. Check for incorrect tire pressure.
  20. Check for uneven or excessive tire wear from suspension misalignment.
  21. Check with operator to see if vehicle is operated under excessive acceleration or is heavily loaded.

Possible Cause & Correction

Check the following items

  1. Fill limiter vent valve stuck closed.
  2. EVAP canister restricted.
  3. EVAP vent valve stuck closed.
  4. Restricted vapor lines.
  5. High reid vapor pressure or high fuel temperature.
  6. Fuel filler hose is pinched or kinked.
  7. Ignition switch on (EVAP vent valve closed).

Check the following items

  1. Pressure relief valve is stuck open or leaking.
  2. Fill limiter vent valve is stuck open or leaking.

Cause & Correction

Check the following items

  1. Fill limiter vent valve stuck closed.
  2. EVAP canister restricted.
  3. EVAP vent valve stuck closed.
  4. Restricted vapor lines.
  5. High reid vapor pressure or high fuel temperature.
  6. Ignition switch on (EVAP vent valve closed).

Check the following items

  1. EVAP canister restricted.
  2. High reid vapor pressure or high fuel temperature.
  3. Check valve stuck closed.

Check the following items

  1. Fill limiter vent valve stuck open or leaking.
  2. Overfilled fuel tank (topping off fuel tank).

Check the following items

  1. Pressure relief valve in fill limiter vent valve is stuck open or leaking.
  2. Fuel filler pipe loose or ruptured.
  3. Leaking fuel tank (seepage).

Check the following items

  1. Pressure relief valve is stuck open or leaking.
  2. Saturated EVAP canister.
  3. Seepage from fuel tank.

Check the following items

  1. Check TP sensor for sticking and binding. Check for correct TP sensor voltage. See FUEL SYSTEMS in appropriate SERVICE & ADJUSTMENT SPECIFICATIONS article.
  2. Check to see if condition is caused by engine running either rich or lean.
  3. Check Park Neutral Position (PNP) switch circuit. Ensure PNP switch is properly adjusted.
  4. Check for poor quality or alcohol contaminated fuel.
  5. Check in-line fuel filter. Replace if dirty or clogged.
  6. Check intake and exhaust manifold passages for casting flash.
  7. Check fuel system for incorrect fuel pressure. See BASIC FUEL SYSTEM CHECKS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  8. Check fuel injectors. Perform injector balance test. See FUEL INJECTOR BALANCE TEST under FUEL SYSTEMS in appropriate SYSTEM & COMPONENT TESTING article.
  9. Check exhaust system for restrictions, such as a damaged or collapsed pipe, muffler or catalytic converter. See EXHAUST SYSTEM BACKPRESSURE under MECHANICAL INSPECTION in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  10. Check for fuel in pressure regulator vacuum hose. If fuel is present, replace regulator.
  11. Check injector harness locations. Ensure injectors are connected to correct injector/cylinder according to firing order.
  12. If rough idle occurs only when engine is hot, check PCV valve for proper operation. Check evaporative emission control system.
  13. Check PCV system for proper operation.
  14. Check engine compression. Check for incorrect valve timing, bent push rods, broken valve springs or worn camshaft lobes.
  15. Remove spark plugs and check for wet plugs, cracks, improper gap, burned electrodes or heavy carbon deposits. Also, check condition of spark plug wires. Spray spark plug wires with a fine mist of water to check for shorts.
  16. Ensure initial ignition timing is properly set.
  17. Check Knock Sensor (KS) system for excessive retard.
  18. Check engine idle speed (both base and PCM idle).
  19. Check Idle Air Control (IAC) system. Check for foreign material in IAC bore.
  20. Check EGR system for proper operation.
  21. Check Power Steering Pressure (PSP) switch circuit.

Check for the following items

  1. Ensure park/neutral switch is properly adjusted.
  2. Check transmission shift solenoid system and Torque Converter Clutch (TCC) system for proper operation.
  3. Ensure owner understands operation of TCC and A/C compressor clutch, as stated in owners manual.
  4. Check exhaust system for restrictions, such as a damaged or collapsed pipe, muffler or catalytic converter. See EXHAUST SYSTEM BACKPRESSURE under MECHANICAL INSPECTION in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  5. Check engine compression. Check for incorrect valve timing, bent push rods, broken valve springs or worn camshaft lobes.
  6. Visually check vacuum hoses for splits, kinks and proper connections as shown on vehicle emission control information label.
  7. Check for proper Crankshaft Position (CKP) and Camshaft Position (CMP) sensor resistance. Check for intermittent ignition feed or ground circuits.
  8. Ensure initial ignition timing is properly set.
  9. Using Spark Tester (J-26792), check for adequate spark output.
  10. Remove spark plugs, and check for wet/fouled spark plugs, cracks in porcelain, improper gap, burned electrodes or heavy carbon deposits. Check spark plug wires.
  11. Check Knock Sensor (KS) system for excessive retard.
  12. Check in-line fuel filter. Replace if dirty or clogged.
  13. Check fuel for water contamination.
  14. Check fuel system for incorrect fuel pressure. See BASIC FUEL SYSTEM CHECKS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  15. Check fuel injectors. Perform injector balance test. See FUEL INJECTOR BALANCE TEST under FUEL SYSTEMS in appropriate SYSTEM & COMPONENT TESTING article.
  16. If emission test shows excessive oxides of nitrogen (NOx) emissions, check all systems and components which could cause engine to run lean or to run too hot. Check EGR system. Check for an inoperative cooling fan.
  17. Check canister purge system for proper operation.
  18. Check EGR valve for proper operation.
  19. Check Heated Oxygen Sensor (HO2S) for contamination. This will cause a false high voltage signal to PCM. PCM will respond by leaning out air/fuel ratio.
  20. Check PCM grounds. Ensure they are clean, tight and properly located.
  21. Check charging system output. Repair if output is less than 9 volts or greater than 16 volts.

CUTS OUT &/OR MISSES

Note. Before continuing with diagnosis, refer to Technical Service Bulletin (TSB) 01-06-04-050, dated 10-19-2001. See DECREASED ENGINE PERFORMANCE/POWER, FILTER MINDER INDICATOR ON, POSSIBLE MIL ILLUMINATED & DTC P0101/P0103 SET (REPLACE AIR CLEANER/REPROGRAM ECM) .

Check the following items

  1. Check engine for low compression. Check for incorrect valve timing, bent push rods, broken valve springs or worn camshaft lobes.
  2. Check for water contaminated fuel.
  3. Inspect fuel delivery system. Check for low fuel pressure, restriction or air in fuel system. See BASIC FUEL SYSTEM CHECKS (DIESEL) in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  4. Check intake and exhaust manifold passages for casting flash or restrictions.

Check the following items

  1. Check fuel quality.
  2. Check fuel injection pump and timing. See appropriate ON-VEHICLE ADJUSTMENTS article.
  3. Check injector nozzles. See appropriate SYSTEM & COMPONENT TESTING article.
  4. Check Engine Coolant Temperature (ECT) sensor, Reading should be within 5°F of ambient air temperature on a cold engine.
  5. Check air filter, turbocharger and air intake system for a restriction.
  6. Check for incorrect basic engine parts such as camshaft, cylinder heads and pistons.
  7. Check for excessive blow-by.

Check the following items

  1. Check coolant level. Check cooling system thermostat for proper operation and application.
  2. Check for restricted airflow to radiator or restricted coolant flow through radiator.
  3. Check for loose water pump belt.
  4. Check Engine Coolant Temperature (ECT) sensor, Reading should be within 5°F of ambient air temperature on a cold engine.
  5. Check fuel injection pump and timing. See appropriate ON-VEHICLE ADJUSTMENTS article.
  6. Check injector nozzles. See appropriate SYSTEM & COMPONENT TESTING article.
  7. Inspect fuel delivery system. Check for no fuel to injection pump or air in fuel system. See BASIC FUEL SYSTEM CHECKS (DIESEL) in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  8. Check for incorrect basic engine parts such as camshaft, cylinder heads and pistons.
  9. Check for excessive blow-by.

Check the following items

  1. Check engine shutoff solenoid operation. Check electrical connections.
  2. Check air filter, turbocharger and air intake system for a restriction.
  3. Check glow plug operation. Check and/or replace glow plugs or controls.
  4. Check for plugged fuel return system for restrictions.
  5. Check fuel cap vent.
  6. Check for slow engine cranking.
  7. Check engine for low compression. Check for incorrect valve timing, bent push rods, broken valve springs or worn camshaft lobes.
  8. Inspect fuel delivery system. Check for no fuel to injection pump or air in fuel system. See BASIC FUEL SYSTEM CHECKS (DIESEL) in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  9. Check for incorrect or contaminated fuel.
  10. Check for incorrect pump timing. See appropriate SELF-DIAGNOSTICS article.
  11. Check Engine Coolant Temperature (ECT) sensor, Reading should be within 5°F of ambient air temperature on a cold engine.

HESITATION, SAG &/OR STUMBLE

Note. Before continuing with diagnosis, refer to Technical Service Bulletin (TSB) 01-06-04-050, dated 10-19-2001. See DECREASED ENGINE PERFORMANCE/POWER, FILTER MINDER INDICATOR ON, POSSIBLE MIL ILLUMINATED & DTC P0101/P0103 SET (REPLACE AIR CLEANER/REPROGRAM ECM) .

Check the following items

  1. Check injector nozzles. See appropriate SYSTEM & COMPONENT TESTING article.
  2. Inspect fuel delivery system. Check for no fuel to injection pump or air in fuel system. See BASIC FUEL SYSTEM CHECKS (DIESEL) in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  3. Check for water contaminated fuel.
  4. Check charging system output. Repair charging system if voltage is less than 9 volts or more than 16 volts.

LACK OF POWER, SLUGGISHNESS OR SPONGINESS

Note. Before continuing with diagnosis, refer to Technical Service Bulletin (TSB) 01-06-04-050, dated 10-19-2001. See DECREASED ENGINE PERFORMANCE/POWER, FILTER MINDER INDICATOR ON, POSSIBLE MIL ILLUMINATED & DTC P0101/P0103 SET (REPLACE AIR CLEANER/REPROGRAM ECM) .

Check the following items

  1. Check injector nozzles. See appropriate SYSTEM & COMPONENT TESTING article.
  2. Inspect fuel delivery system. Check for no fuel to injection pump or air in fuel system. See BASIC FUEL SYSTEM CHECKS (DIESEL) in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  3. Check air filter, turbocharger and air intake system for restriction.
  4. Check for incorrect pump timing. See appropriate SELF-DIAGNOSTICS article.
  5. Check oil level and quality.
  6. Inspect fuel quality.
  7. Check control module grounds for correct locations, tight and clean connections. See WIRING DIAGRAMS article.
  8. Check transmission for proper shifting and Torque Converter Clutch (TCC) system for proper operation.
  9. Check engine for low compression. Check for incorrect valve timing, incorrect or worn camshaft.
  10. Inspect fuel delivery system. Check for low fuel pressure, restriction or air in fuel system. See BASIC FUEL SYSTEM CHECKS (DIESEL) in appropriate BASIC DIAGNOSTIC PROCEDURES article.
  11. Check charging system output. Repair charging system if voltage is less than 9 volts or more than 16 volts.
  12. Check A/C for proper operation.
  13. Check for worn or damaged turbocharger turbine wheel, shaft or compressor wheel.
  14. Check for air leaks or restrictions in intake air system or manifold.
  15. Check for a restricted or leaking exhaust system.
  16. Check injector nozzles. See appropriate SYSTEM & COMPONENT TESTING article.

POOR FUEL ECONOMY

Note. Before continuing with diagnosis, refer to Technical Service Bulletin (TSB) 01-06-04-050, dated 10-19-2001. See DECREASED ENGINE PERFORMANCE/POWER, FILTER MINDER INDICATOR ON, POSSIBLE MIL ILLUMINATED & DTC P0101/P0103 SET (REPLACE AIR CLEANER/REPROGRAM ECM) .

Check the following items

  1. Check transmission for proper shifting and Torque Converter Clutch (TCC) system for proper operation.
  2. Visually check vacuum hoses for splits, kinks and proper connections as shown on vehicle emission control information label.
  3. Check fuel quality.
  4. Check for dragging brakes.
  5. Check for incorrect tire pressure.
  6. Check with operator to see if vehicle is operated under excessive acceleration or is heavily loaded.
  7. Check A/C for "full time" operation.
  8. Check coolant level. Check engine cooling system thermostat for proper heat range and operation.
  9. Check air filter, turbocharger and air intake system for a restriction.
  10. Inspect fuel delivery system. Check for low fuel pressure, restriction or air in fuel system. See BASIC FUEL SYSTEM CHECKS (DIESEL) in appropriate BASIC DIAGNOSTIC PROCEDURES article.

Check the following items

  1. Check for incorrect pump timing. See appropriate SELF-DIAGNOSTICS article.
  2. Ensure owner understands operation of TCC and A/C clutch operation, as stated in owners manual.
  3. Check injector nozzles. See appropriate SYSTEM & COMPONENT TESTING article.
  4. Ensure Vehicle Speed Sensor (VSS) reading matches vehicle speedometer reading.
  5. Check charging system output. Repair charging system if voltage is less than 9 volts or more than 16 volts.
  6. Check transmission for proper shifting and Torque Converter Clutch (TCC) system for proper operation.
  7. Check control module grounds for correct locations, tight and clean connections. See WIRING DIAGRAMS article.
  8. Visually check vacuum hoses for splits, kinks and proper connections as shown on vehicle emission control information label.

PROBABLE CAUSES

  1. Clogged air filter element.
  2. Obstructed air intake duct to turbo compressor.
  3. Obstructed air outlet duct from compressor to intake manifold.
  4. Obstructed intake manifold.
  5. Air leak in duct from air cleaner to compressor.
  6. Air leak in duct from compressor to intake manifold.
  7. Air leak at intake manifold-to-engine joint.
  8. Obstruction in exhaust manifold.
  9. Obstruction in exhaust system.
  10. Gas leak in exhaust manifold-to-engine joint.
  11. Gas leak in turbine inlet-to-exhaust manifold joint.
  12. Gas leak in ducts after turbine outlet.
  13. Obstructed turbocharger oil drain line.
  14. Obstructed engine crankcase ventilation.
  15. Turbocharger center housing sludged or coked.
  16. Engine camshaft timing incorrect.
  17. Worn engine piston rings or liners (blow-by).
  18. Internal engine problems (valves or pistons).
  19. Dirt caked on compressor wheel and/or diffuser vanes.
  20. Damaged turbocharger.
  21. Wastegate stuck open.

Intermittent Simulation

Use the following methods to reproduce conditions causing intermittent

  1. Apply light vibration to components.
  2. Heat component.
  3. Wiggle or bend wiring harness.
  4. Spray component with water.
  5. Remove/apply vacuum supply source.

Monitor circuit/component voltage or resistance while attempting to simulate intermittent. If vehicle is running, monitor for DTCs. Use test results to identify faulty component or circuit.

Use the following procedures to determine possible causes of intermittent MIL operation

  1. Check for poor mating of one connector to another. Terminals may not be fully seated. Check for improperly formed or damaged terminals. Check wire-to-terminal connections.
  2. Check for poor connection from ignition coil to ground or arcing at spark plug wires or plugs.
  3. Check for poor connections in PCM ground terminals.
  4. Check for electrical system interference caused by defective relay, PCM-driven solenoid or switch, which may cause sharp electrical surge. This type of problem will normally occur when faulty component are operated.
  5. Check for aftermarket parts which may not have been produced to manufacturer's specifications. Check for solenoids or relays without original equipment diodes for circuit protection.
  6. Check for improper installation of electrical accessories such as theft deterrent devices, auxiliary lights, cellular phone etc.
  7. Ensure Ignition Control (IC) module wiring is kept away from spark plug wires, ignition coil and generator. Ensure ground wire from PCM to IC module is connected to a good ground.
  8. Check for intermittent short to ground on data circuits of Data Link Connector (DLC) or in MIL circuit. See WIRING DIAGRAMS article.
  9. On vehicles not equipped with a driver information center, use scan tool to check for intermittent wiring problem. See SCAN TOOL USAGE under SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article.

Note. If a problem cannot be located, a cellular phone communication signal may be the cause.

More articles — Engine Controls - Trouble Shooting - No Codes