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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1350 (Engine Control System (Troubleshooting & Diagnosis) -- 1.8L (LNK)) >> Troubleshooting >> Engine Cranks but Does Not Run >> Test Description

Test Description

WARNING: This page is about a different car, the 2004 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step numbers on the diagnostic table.

  1. 1:  The Diagnostic System Check-Engine Controls prompts the technician to complete some basic checks and store the Freeze Frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.
  2. 2:  If a fuse is found to be the cause of the no start, locate and repair any shorts that may have caused the fuse to open before replacing the fuse.
  3. 3:  If there is a fault in either the CKP sensor or CMP sensor circuits, the ignition system can malfunction. Repair the cause of a DTC P0335, P0339, P0340, or P0341 first.
  4. 4:  If there is a fault in the electrical circuits between the PCM and the ignition coil assemblies, a DTC P0351-P0354 will set. Use the DTC P0351-P0354 diagnostic table in order to repair the ignition system failure.
  5. 5:  The fuel mixture may be too rich or too lean to start the engine if the engine coolant temperature (ECT) sensor signal is incorrect.
  6. 6:  The fuel mixture may be too rich or too lean to start the engine if the throttle position (TP) sensor signal is incorrect.
  7. 7:  The fuel mixture may be too rich or too lean to start the engine if the mass air flow (MAF) sensor signal is incorrect.
  8. 11:  This step verifies if there is any fuel pressure. If there is no fuel pressure the fuel pump electrical circuit must be inspected.
  9. 17:  This step verifies if the engine will start and run. The repair that may have led to this step may only have been a secondary cause of the no start condition, such as fouled spark plugs. The diagnostics in this table may need to be performed a second time in order to discover the root cause of the no start condition.
Engine Cranks but Does Not Run

Step Action Values Yes No
Schematic Reference:  Engine Controls Schematics 
Connector End View Reference:  Powertrain Control Module (PCM) Connector End Views  or  Engine Controls Connector End Views 
1  Did you perform the Diagnostic System Check-Engine Controls? - Go to Step 2  Go to Diagnostic System Check - Engine Controls
2 
  1. Check the IGN fuse in junction block 2 or the EFI fuse in the fuse and relay box 1 for any of the following conditions:
    • Open condition
    • No supplied power
    • Faulty terminal connections
  2. Repair as necessary.
Was a repair necessary?		 - Go to Step 17  Go to Step 3 
3  Check for any DTCs with a scan tool.
Is a DTC P0335, P0339, P0340, or P0341 set?		 - Go to Diagnostic Trouble Code (DTC) List Go to Step 4 
4  Is a DTC P0351, P0352, P0353, or P0354 set? - Go to DTC P0351-P0354 Go to Step 5 
5 
  1. Turn ON the ignition, with the engine OFF.
  2. Observe the ECT sensor parameter on the scan tool.
Is the coolant temperature displayed on the scan tool near the actual coolant temperature?		 - Go to Step 6  Go to DTC P0115
6  Observe the TP sensor parameter on a scan tool with the throttle closed.
Is the throttle position opening displayed on the scan tool within the specified range?		 0-23% Go to Step 7  Go to DTC P0121
7 
  1. Observe the MAF sensor reading on the scan tool while cranking the engine.
  2. Compare the observed MAF reading to the specified value.
Is the MAF reading within the specified range?		 1.80-3.95 g/s Go to Step 8  Go to DTC P0101
8
  1. Turn OFF the ignition.
  2. Disconnect all four fuel injector electrical connectors.
  3. Install a J 34730-2B  Fuel Injector Test Lamp, or equivalent, into each fuel injector harness connector.
  4. Observe the injector test lamp for each fuel injector while cranking the engine.
Did the fuel injector test lamp flash for each injector while cranking the engine?		 - Go to Step 9  Go to Fuel Injector Circuit Diagnosis 
9
  1. Disconnect the electrical connector of each fuel injector.
  2. Disconnect the electrical connector at an ignition coil assembly.
  3. Remove the ignition coil assembly. Refer to Ignition Coil(s) Replacement . Do not remove the spark plugs.
  4. Connect a J 26792  Spark Tester or an equivalent to the spark plug boot of the ignition coil assembly.
  5. Clip the spark tester to ground.
  6. Connect the coil assembly electrical connector.
  7. Crank the engine and observe the spark tester.
  8. Repeat this test for each ignition coil assembly.
Is a crisp blue spark available at all ignition coil assemblies?		 - Go to Step 10  Go to Electronic Ignition (EI) System Diagnosis 
10
  1. Inspect the spark plugs for correct operation and condition. Refer to Spark Plug Inspection .
  2. Clean or replace the spark plugs as necessary. Refer to Spark Plug Replacement .
Was a repair or replacement necessary?		 - Go to Step 17  Go to Step 11 
11 
  1. Verify that the vehicle has an adequate supply of fuel in the fuel tank.
  2. Install the J 34730-1A  Fuel Pressure Gage or an equivalent. Refer to Fuel Pressure Gage Installation and Removal .
  3. Turn ON the ignition, with the engine OFF.
  4. Select Fuel Pump in the Engine Output Controls menu.
  5. Turn the fuel pump relay ON for 5 seconds with the scan tool.
  6. Check the fuel pressure reading on the fuel pressure gage.
Is the fuel pressure indicated within the specified range?		 301-347 kPa (44-50 psi) Go to Step 13  Go to Step 12 
12
  1. Turn the fuel pump relay ON for 5 seconds with the scan tool.
  2. Check the fuel pressure reading on the fuel pressure gage.
Is the fuel pressure indicated more the specified range?		 0-7 kPa
(0-1.0 psi)		 Go to Fuel System Diagnosis  Go to Fuel Pump Electrical Circuit Diagnosis 
13
  1. Inspect a fuel sample for the following concerns:
  2. Replace the fuel as necessary.
Did you find and correct a condition?		 - Go to Step 17  Go to Step 14 
14
  1. Check for clean and tight electrical grounds at all of the following locations:
    • G104 and G105
    • G203
    • The PCM ground terminals
  2. Repair as necessary.
Did you find and correct a condition?		 - Go to Step 17  Go to Step 15 
15
  1. Inspect the engine for any of the following engine mechanical concerns:
    • Worn or faulty camshaft
    • Leaking or sticking valves
    • Excessive valve deposits
    • Weak or broken valve springs
    • Incorrect valve timing
    • Intake gasket leaks
    • Engine vacuum leaks
    • Leaking or broken piston rings
    • Low engine compression
  2. Refer to Diagnostic Starting Point - Engine Mechanical in Engine Mechanical - 1.8L (LNK).
Was an engine mechanical concern found and repaired?		 - Go to Step 17  Go to Step 16 
16 Inspect the exhaust system for excessive back pressure. Refer to Restricted Exhaust in Engine Exhaust.
Was an exhaust system repair or replacement necessary?		 - Go to Step 17  Go to Diagnostic Aids
17 
  1. Perform the scan tool Clear DTC Information function.
  2. Attempt to start the engine.
Does the engine start and continue to run?		 - Go to Step 18  Go to Step 2 
18
  1. Operate the engine at idle until a normal operating temperature is reached.
  2. Check for DTCs with a scan tool.
Are any DTCs displayed?		 - Go to Diagnostic Trouble Code (DTC) List Go to Step 19 
19 With the scan tool review the stored information, Capture Info.
Does the scan tool display any DTCs that you have not diagnosed?		 - Go to Diagnostic Trouble Code (DTC) List System OK
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