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.

Check for any related TSBs.
Turn the ignition off.

NOTE: Wait a minimum of 8 minutes to allow the O2 Sensor to cool down before continuing the test.

Ignition on, engine not running.

With the DRBIII®, actuate the O2 Heater Test.

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

Does the voltage stabilize between 0.1 and 0.3 of a volt during the Heater test?
1. Yes --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure).
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
2. No --> Go To 2
Turn the ignition off.
NOTE: Allow the O2 Sensor to cool to room temperature.

Disconnect the O2 Sensor harness connector.

Measure the resistance across the O2 Sensor Heater element component side.

NOTE: O2 Heater Element resistance values should be measured at 70°F (21.1°C). The resistance value will vary with different temperature values.

Is the resistance of the O2 Sensor Heater Element between 2.0 and 30.0 ohms?
1. Yes --> Go To 3
2. No --> Replace the O2 Sensor.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .

NOTE: The O2 Heater Supply circuit may be a fused (A141) ASD Relay Output or an O2 Sensor (A42) Heater Relay Output, depending on the O2 Sensor being tested.

Ignition on, engine not running and the O2 Sensor still disconnected.
With the DRBIII®, actuate the O2 Heater Test.

Using a 12-volt test light connected to ground, probe the (A141) Fused ASD Relay Output or (A42) O2 Heater Relay Output circuit at the O2 Sensor harness connector..

Does the light illuminate brightly?
1. Yes --> Go To 4
2. No --> Repair the open in the (A141) Fused ASD Relay Output circuit or the (A42) O2 Heater Relay Output circuit.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
Turn the ignition off.
Disconnect the PCM harness connectors.

Remove the O2 Heater Relay, if it applies to the O2 Sensor being tested.

* Measure the resistance of the O2 Heater Control circuit (PWM) from the O2 Sensor to the PCM harness connector if it applies to the O2 Sensor being tested.

OR

* Measure the resistance of the (K127) O2 Heater Relay Control circuit from the O2 Heater Relay to the PCM harness connector, if it applies to the O2 Sensor being tested.

Is the resistance below 5.0 ohms?
1. Yes --> Go To 5
2. No --> Repair the excessive resistance in the O2 Heater Control circuit.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .

NOTE: Before beginning this test, verify what type of Heated O2 Sensor is being tested, either the PWM Heated O2 Sensor or the Heater Relay controlled Heated O2 Sensor.

* Measure the resistance between ground and the O2 Heater Control (PWM) circuit if it applies to the O2 Sensor being tested.
OR

* Measure the resistance between ground and the (K127) O2 Heater Relay Control circuit at the PCM harness connector.

Is the resistance below 100 ohms?
1. Yes --> Repair the short to ground in the O2 Heater Control circuit.
  Perform POWERTRAIN VERIFICATION TEST VER - 5 .
2. No --> Go To 6

NOTE: If the O2 Sensor being tested does not use an O2 Heater Relay to supply voltage to the O2 Sensor Heater, answer YES to this test and continue.

Using a 12-volt test light connected to 12-volts, probe the (Z192) or (Z193) O2 Heater Ground circuit.
Does the test light illuminate brightly?
1. Yes --> Go To 7
2. No --> Repair the open in the O2 Sensor Heater 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 .