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.
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 - 6 .
Turn the ignition off.
Disconnect the vacuum supply hose at the Leak Detection Pump.

Connect a vacuum gauge to the disconnected vacuum supply hose at the Leak Detection Pump.

Start the engine and read the vacuum gauge.

Does the vacuum gauge read at least 13" Hg?
1. Yes --> Go To 3
2. No --> Repair leak or obstruction in vacuum hose as necessary.
  Perform POWERTRAIN VERIFICATION TEST VER - 6 .
Turn the ignition off.
Connect the vacuum supply hose at the LDP.

Disconnect the Leak Detection Pump electrical harness connector.

Start the engine.
With the DRBIII® in Inputs/Outputs, read the Leak Detect Pump Switch state.
Connect a jumper wire between 12-volts and the (K107) LDP Switch Signal circuit.

Did the Leak Detect Pump Sw state change when the jumper was connected?
1. Yes --> Replace the Leak Detection Pump.
  Perform POWERTRAIN VERIFICATION TEST VER - 6 .
2. No --> Go To 4
NOTE: Remove the jumper wire before continuing.
Turn the ignition off.
Disconnect the PCM harness connectors.

Measure the resistance of the (K107) LDP Switch Sense circuit from the PCM harness connector to LDP harness connector.

Is the resistance below 5.0 ohms?
1. Yes --> Go To 5
2. No --> Repair the open in the (K107) Leak Detection Pump Switch Sense circuit.
  Perform POWERTRAIN VERIFICATION TEST VER - 6 .
Measure the resistance between ground and the (K107) LDP Switch Sense circuit.
Is the resistance below 100 ohms?
1. Yes --> Repair the short to ground in the (K107) LDP Switch Sense circuit.
  Perform POWERTRAIN VERIFICATION TEST VER - 6 .
2. No --> Go To 6

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 - 6 .