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 contaminates that may have damaged the O2 Sensor: contaminated fuel, unapproved silicone, oil and coolant.

NOTE: Any O2 Sensor, TPS, ECT, MAP, or EVAP DTCs must be repaired before continuing.

Ignition on, engine not running.
With the DRBIII®, read DTCs and record the related Freeze Frame data.

Is the Good Trip Counter displayed and equal to zero?
1. Yes --> Go To 2
2. No --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure).
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
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.

Install a fuel pressure gauge.

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 (49.2 psi +/- 5 psi).

Choose a conclusion that best matches your fuel pressure reading.
1. Within Specification
  1. Go To 3
2. Above Specification
  1. Replace the fuel filter/pressure regulator.
  2. Perform POWERTRAIN VERIFICATION TEST VER - 5 .
CAUTION: Stop All Actuations.
Ignition on, engine not running.
With the DRBIII®, monitor all of the O2 Sensor voltage readings.

Is the voltage above 4.5 volts for all of the O2 Sensors?
1. Yes --> Go To 4
2. No --> Go To 11
Turn the ignition off.
NOTE: Wait a minimum of 10 minutes to allow the O2 Sensor to cool down before continuing the test. Allow the O2 Sensor voltage to stabilize between 4 and 5 volts.

Ignition on, engine not running.

With the DRBIII®, actuate the O2 Heater Test.

With the DRBIII®, monitor all of the O2 Sensor voltage values for at least 2 minutes.

Does the voltage stay above 4.5 volts on any of the O2 Sensors?
1. Yes --> Replace the O2 Sensor that had the voltage reading above 4.5 volts.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
2. No --> Go To 5

NOTE: The engine must be at operating temperature and in closed loop to perform this test.

WARNING: WHEN THE ENGINE IS OPERATING, DO NOT STAND IN A DIRECT LINE WITH THE PAN. DO NOT PUT YOUR HANDS NEAR THE PULLEYS, BELTS OR FAN. DO NOT WEAR LOOSE CLOTHING.

NOTE: Short Term Adaptive value change.

Start the engine.
Allow the engine to reach normal operating temperature.

With the DRBIII® select System Tests, perform the Purge Vapors Test.

Observe the Short Term Adaptive value and press 3 to flow.

Did the Short Term Adaptive value change?
1. Yes --> Go To 6
2. No --> Refer to the Driveability category and perform the appropriate Diagnostic test.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
Ignition on, engine not running.
With the DRBIII®, read TP Sensor voltage.

NOTE: The throttle must be against the stop.

Is the voltage 0.92 of a volt or less with the Throttle closed?
1. Yes --> Go To 7
2. No --> Check for a binding throttle condition. If OK, replace the Throttle Position Sensor.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
With the DRBIII®, read the TP Sensor voltage.
While monitoring the DRBIII®, slowly open and close the throttle.

Does the voltage increase and decrease smoothly?
1. Yes --> Go To 8
2. No --> Replace the Throttle Position Sensor.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
Turn the ignition off.
Connect a Vacuum Gauge to a Manifold Vacuum source.

Start the engine.

Allow the engine to idle.

NOTE: If engine will not idle, maintain a constant RPM above idle.

With the DRBIII® in Sensors, read the MAP Sensor vacuum value.

Is the DRBIII® reading within 1" of the Vacuum Gauge reading?
1. Yes --> Go To 9
2. No --> Replace the MAP Sensor.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
NOTE: Remove the vacuum gauge before continuing.

NOTE: For this test to foe valid, the thermostat must be operating correctly.

NOTE: This test works best if performed on a cold engine (cold soak)

NOTE: If engine coolant temperature is above 82°C (180°F), allow the engine to cool until 65°C (150°F) is reached.

Ignition on, engine not running.
With the DRBIII®, read the Engine Coolant Temperature Sensor value. If the engine was allowed to sit overnight (cold soak), the temperature value should be a sensible value that is somewhere close to the ambient temperature.

Start the Engine.

During engine warm-up, monitor the Engine Coolant Temperature value. The temp value change should be a smooth transition from start up to normal operating temp 82°C (180°F). The value should reach at least 82°C (180°F).

Did the Engine Coolant Temperature value increase smoothly and reach at least 82°C?
1. Yes --> Go To 10
2. No --> Replace the Engine Coolant Temperature Sensor.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
Check for any of the following conditions/mechanical problems.
AIR INDUCTION SYSTEM - must be free from restrictions.

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

FUEL INJECTOR - plugged or restricted injector; control wire not connected to correct injector

Are there any engine mechanical problems?
1. Yes --> Repair as necessary.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
2. No --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure).
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
Disconnect the sensor harness connector of the O2 Sensor(s) that had a voltage value greater than 4.5 volts in the previous step.
Ignition on, engine not running.

With the DRBIII®, monitor the O2 Sensor voltage reading(s).

Is the O2 Sensor voltage above 4.5 volts?
1. Yes --> Replace the O2 Sensor that had the voltage reading above 4.5 volts.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
2. No --> Go To 12
Turn the ignition off.
Disconnect the PCM harness connectors.

Measure the resistance of the O2 Sensor Signal circuit from the PCM harness connector to the O2 Sensor harness connector.

Is the resistance below 5.0 ohms?
1. Yes --> Go To 13
2. No --> Repair the open in the O2 Sensor Signal circuit.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
Ignition on, engine not running.
Leave the O2 Sensor and PCM harness connectors disconnected.

Measure the voltage on the O2 Sensor Signal circuit at the O2 Sensor harness connector.

Is the voltage above 5.2 volts?
1. Yes --> Repair the short to voltage in the O2 Sensor Signal circuit.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
2. No --> Go To 14
NOTE: Turn the ignition off before continuing.

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 .