Diagnostics Procedures

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.

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.
Disconnect the IAT Sensor harness connector.

Disconnect the PCM harness connectors.

NOTE: Visually inspect both the component and the PCM connectors. Look for damaged, partially broken wires, and backed out or corroded terminals.

Ignition on, engine not running.

Using a 12-volt test light connected to ground, probe the (K21) IAT Signal circuit in the IAT Sensor harness connector.

Does the test light illuminate brightly?
1. Yes --> Repair the short to voltage in the (K21) IAT Signal circuit.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
2. No --> Go To 3
Turn the ignition off.
Connect the PCM harness connectors.

Ignition on, engine not running.

With the DRBIII®, read the IAT voltage.

Is the voltage above 4.6 volts?
1. Yes --> Go To 4
2. No --> Go To 7
Connect a jumper wire between the (K21) IAT Signal circuit and (K900) Sensor ground circuit in the IAT Sensor harness connector.
With the DRBIII®, read the IAT voltage.

Is the voltage below 1.0 volt?
1. Yes --> Replace the IAT Sensor.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
2. No --> Go To 5
NOTE: Remove the jumper wire before continuing.
Turn the ignition off.
Disconnect the PCM harness connectors.

CAUTION: DO NOT PROBE THE PCM HARNESS CONNECTORS. PROBING THE PCM HARNESS CONNECTORS WILL DAMAGE THE PCM TERMINALS RESULTING IN POOR TERMINAL TO PIN CONNECTION. INSTALL MILLER SPECIAL TOOL #8815 TO PERFORM DIAGNOSIS.

Measure the resistance of the (K21) IAT Signal circuit from the IAT Sensor harness connector to the appropriate terminal of special tool #8815.

Is the resistance below 5.0 ohms?
1. Yes --> Go To 6
2. No --> Repair the open in the (K21) IAT Signal circuit.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .

CAUTION: DO NOT PROBE THE PCM HARNESS CONNECTORS. PROBING THE PCM HARNESS CONNECTORS WILL DAMAGE THE PCM TERMINALS RESULTING IN POOR TERMINAL TO PIN CONNECTION. INSTALL MILLER SPECIAL TOOL #8815 TO PERFORM DIAGNOSIS.

Measure the resistance of the (K900) Sensor ground circuit from the IAT Sensor harness connector to the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?
1. Yes --> Go To 9
2. No --> Repair the open in the (K900) Sensor ground circuit.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
Turn the ignition off.
Disconnect the PCM harness connectors.

Measure the resistance between ground and the (K21) IAT Signal circuit in the IAT Sensor harness connector.

Is the resistance below 100 ohms?
1. Yes --> Repair the short to ground in the (K21) IAT Signal circuit.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
2. No --> Go To 8
Measure the resistance between the (K900) Sensor ground circuit and the (K21) IAT Signal circuit at the IAT Sensor harness connector.
Is the resistance below 5.0 ohms?
1. Yes --> Repair the short between the (K900) Sensor ground circuit and the (K21) IAT Signal circuit.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
2. No --> Go To 9

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 .