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 the IAT voltage.

Is the voltage above 4.98 volts?
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 harness connector.

Connect a jumper wire between the (K21) IAT Signal circuit and the (K900) Sensor ground circuit in the IAT harness connector.

Ignition on, engine not running.

With the DRBIII®, read 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 3
NOTE: Remove the jumper wire before continuing.
Turn the ignition off.
Disconnect the PCM harness connectors.

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 4
Turn the ignition off.
CAUTION: DO NOT PROBE THE PCM HARNESS CONNECTORS. PROBING THE PCM HARNESS CONNECTORS WELL 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 5
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 WELL 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 6
2. No --> Repair the open in the (K900) Sensor ground circuit.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .

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 .