Diagnostic Procedure

WARNING: This page is about a different car, the 2004 Dodge Pickup and 2004 Dodge Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Refer to VERIFICATION TESTS for appropriate verification test procedures.

NOTE: Check for any TSB's that apply to a Misfire condition. Review the vehicle repair history for any misfire condition repairs that have been performed.

Read and record the FREEZE FRAME DATA. Select OBD II MONITORS. Read and record the MIS-FIRE SIMILAR CONDITIONS WINDOW DATA.
With these screens, attempt to duplicate the condition(s) that has set this DTC.

When the vehicle is operating in the SIMILAR CONDITIONS WINDOW, refer to the WHICH CYLINDER IS MISFIRING screen.

Observe the WHICH CYLINDER IS MISFIRING screen for at least one minute.

Is there a misfire present?
1. Yes --> Go To 2
2. No --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure).
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .

NOTE: Anything that affects the speed of the crankshaft can cause a misfire DTC.

NOTE: When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinders Injector Control circuit.

- Visually inspect the engine for any of the following conditions.
- Worn serpentine belt
- Binding Engine-Driven accessories: A/C Compressor, P/S Pump, Water pump.
- Misalignment Water pump, P/S Pump and A/C Compressor pulleys
- Corroded PCM power and ground circuits.
- Improper CKP, CMP, MAP, and TP Sensor mounting
- Poor connector/terminal to component connection, i.e., CKP sensor, Fuel Injector, Ign coil, etc.
- Vacuum leaks
- Restricted Air Induction system or Exhaust system.
Were any of the above conditions present?
1. Yes --> Repair as necessary.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
2. No --> Go To 3
Turn the ignition off.
Disconnect the Ignition Coil harness connector.

Disconnect the Fuel Injector harness connector.

Ignition on, engine not running.

With the DRBIII®, actuate the ASD Relay.

Using a 12-volt test light connected to ground, probe the (A142) ASD Relay Output circuit at the Ignition Coil harness connector and Fuel Injector harness connector.

Does the test light illuminate brightly?
1. Yes --> Go To 4
2. No --> Repair the excessive resistance or short to ground in the (A142) ASD Relay Output circuit.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
Turn the ignition off.
Connect the Ignition Coil harness connector.

Disconnect the Ignition wire from the spark plug.

Disconnect the Fuel Injector harness connector of the cylinder being tested.

NOTE: Before continuing inspect the ignition wire for damage or carbon tracking. Replace as necessary.

Install a spark tester on the ignition wire.

While cranking the engine observe the spark coming from the spark tester.

NOTE: A crisp blue spark that is able to jump the gap of the spark tester should be generated.

Is good spark present?
1. Yes --> Go To 5
2. No --> Go To 14
NOTE: Connect the Fuel Injector harness connector before continuing.
Turn the ignition off.
Remove the Spark Plug.

Inspect the Spark Plug for the following conditions.
- Cracks
- Carbon Tracking
- Foreign Material
- Gap size out of specifications
- Loose or broke electrode

NOTE: Lightly tap the bottom of the spark plug on a solid surface. The electrode in the spark plug should not move.

Were any of the above condition present?
1. Yes --> Replace the Spark Plug.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
2. No --> Go To 6

WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released.

NOTE: Fuel pressure specification is 334 KPa +/- 34 KPa (49 psi +/- 5 psi).

Install a fuel pressure gauge to the fuel rail.
Start the engine and observe the fuel pressure reading.

Choose a conclusion that best matches your fuel pressure reading.
1. Within Specification
  1. Go To 7
2. Below Specification
  1. Go To 12
3. Above Specification
  1. Replace the fuel filter/pressure regulator.
  2. Perform POWERTRAIN VERIFICATION TEST VER - 5 .

NOTE: Before continuing visually and physically inspect the fuel delivery system for external leaks or damage. Repair /replace as necessary.

WARNING: The fuel system is under a constant pressure even with the engine off. Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released.

NOTE: Fuel specification is 334 KPa +/- 34 KPa (49 psi +/- 5 psi).

NOTE: The pressure should not fall below 241 KPa (35 psi)

Turn the ignition off.
Install special tool #6539 (5/16") or #6631 (3/8") fuel line adapter.

Install the fuel pressure gauge.

Start the engine and allow the fuel system to reach maximum pressure.

Turn the ignition off.

Using special tool #04390, Hose Clamp Pliers, pinch the rubber fuel line between the fuel pressure gauge and the engine.

Monitor the fuel pressure gauge for a minimum of 5 minutes.

Does the fuel pressure gauge fall below the listed specification?
1. Yes --> Replace the leaking Fuel Injector(s).
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
2. No --> Go To 8

WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released.

CAUTION: After each Fuel Injector actuation, start the engine to clean the cylinder of fuel. Failure to do so could cause engine damage.

NOTE: Turn the ignition off, remove the Fuel Pressure gauge, and connect the fuel lines before continuing.

Remove special tool #C4390.
Start the engine and allow the fuel pressure to reach maximum pressure.

Using the DRBIII®, actuate the Fuel Injector for the cylinder that indicated the misfire.

Monitor the fuel pressure gauge.

Does the fuel pressure gauge indicate a drop in fuel pressure?
1. Yes --> Go To 9
2. No --> Go To 10
Check for any of the following conditions/mechanical problems.
ENGINE VACUUM - must be at least 13 inches in neutral

ENGINE VALVE TIMING - must be within specifications

ENGINE COMPRESSION - must be within specifications

ENGINE EXHAUST SYSTEM - must be free of any restrictions or leaks.

ENGINE PCV SYSTEM - must flow freely

TORQUE CONVERTER STALL SPEED - must be within specifications

POWER BRAKE BOOSTER - no internal vacuum leaks FUEL - must be free of contamination CAM LOBES - must not be worn excessively

CYLINDER LEAKAGE TEST - must be within specifications

VALVE SPRINGS - cannot be weak or broken

Are there any engine mechanical problems?
1. Yes --> Repair as necessary.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
2. No --> Go To 17
Turn the ignition off.
Disconnect the Fuel Injector harness connector.

Ignition on, engine not running.

NOTE: When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinders Injector Control circuit.

With the DRBIII®, erase DTCs.

Using a 12-volt test light connected to 12-volts, probe the Injector Control circuit.

With the DRBIII®, actuate the Fuel Injector.

Does the test light blink/flicker?
1. Yes --> Replace the Fuel Injector.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
2. No --> Go To 11
Turn the ignition off.
Disconnect the PCM harness connectors.

Check the Injector Control circuit for an open, short to ground, and short to voltage.

Was a problem found with the Injector Control circuit?
1. Yes --> Repair the excessive resistance or short in the Injector Control circuit.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
2. No --> Go To 17
Turn the ignition off.
WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released.

Raise vehicle on hoist, and disconnect the fuel pressure line at the fuel pump module.

Install special tool #6539 (5/16") #6631(3/8") fuel line adapter and the fuel pressure gauge between the fuel supply line and the fuel pump module.

Ignition on, engine not running.

With the DRBIII®, actuate the ASD Fuel System test and observe the fuel pressure gauge.

NOTE: Fuel pressure specification is 339 KPa +/- 34 KPa (49 psi +/- 5 psi).

Is the fuel pressure within specification?
1. Yes --> Repair or replace fuel supply line as necessary.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
2. No --> Go To 13
Turn the ignition off.
WARNING: The fuel system is under a constant pressure (even with the engine off). Before testing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released.

Remove the Fuel Pump Module and inspect the Fuel Inlet Strainer.

Is the Fuel Inlet Strainer plugged?
1. Yes --> Replace the Fuel Pump Inlet Strainer.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
2. No -->
  NOTE: Before continuing, check the Fuel Pump Module harness connector terminals for corrosion, damage, or terminal push out. Ensure the ground circuit is operating properly. Repair as necessary. Replace the Fuel Pump Module.
  
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .

NOTE: If the vehicle being tested does not have an ignition wire answer YES to this test and continue.

Turn the ignition off.
Remove the ignition wire.

Measure the resistance of the ignition wire.

Is the resistance below 10K ohms?
1. Yes --> Go To 15
2. No --> Replace the Ignition Wire.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
Remove the Fuel Pump Relay or ASD Relay.
Using a 12-volt test light connected to 12-volts, probe the Ignition Coil Control circuit in the Ignition Coil harness connector.

Crank the engine for 5 second while observing the test light.

NOTE: The primary resistance of the 8.0L Ignition coil is 0.53 to 0.65 of an ohm, the resistance of a 5.9L Ignition coil is 0.95 of an to 1.2 ohms, and the resistance of a 3.7L coil is 0.6 to 0.9 of an ohm at 77°F (25°C).

Does the test light brightly blink/flicker?
1. Yes --> Replace the Ignition Coil.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
2. No --> Go To 16
Turn the ignition off.
Disconnect the PCM harness connectors.

Check the Coil Control circuit for an open, short to ground, and short to voltage.

Was a problem found with the Coil Control circuit?
1. Yes --> Repair the Coil Control circuit for an open or shorted condition.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
2. No --> Go To 17

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.
If there are no possible causes remaining, view repair.
1. Repair
  1. Replace and program the Powertrain Control Module per Service Information.
  2. Perform POWERTRAIN VERIFICATION TEST VER - 5 .