Axiom 4WD V6-3.5L (2004)
Malfunction Indicator Lamp: Testing and Inspection
No Malfunction Indicator Lamp (MIL)
No Malfunction Indicator Lamp (MIL)
Circuit Description
The "Check Engine" lamp (MIL) should always be illuminated and steady with the ignition "ON" and the engine stopped. Ignition feed voltage is
supplied to the MIL bulb through the meter fuse. The Engine Control Module (ECM) turns the MIL "ON" by grounding the MIL driver circuit.
Diagnostic Aids
An intermittent MIL may be cased by a poor connection, rubbed-through wire insulation, or a wire broken inside the insulation. Check for the following
items:
-
Inspect the ECM harness and connections for improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wire
connection, and damaged harness.
-
If the engine runs OK, check for a faulty light bulb, an open in the MIL driver circuit, or an open in the instrument cluster ignition feed.
-
If the engine cranks but will not run, check for an open ECM ignition or battery feed, or a poor ECM to engine ground.
Test Description
Number(s) below refer to the step number(s) on the Diagnostic Chart.
2. A "No MIL" condition accompanied by a no-start condition suggests a faulty ECM ignition feed or battery feed circuit.
9. Using a test light connected to B+, probe each of the ECM ground terminals to ensure that a good ground is present. Refer to ECM Terminal End
View for terminal locations of the ECM ground circuits.
12. In this step, temporarily substitute a known good relay for the ECM relay. The horn relay is nearby, and it can be verified as "good" simply by
honking the horn. Replace the horn relay after completing this step.
17. This vehicle is equipped with a ECM which utilizes an electrically erasable programmable read only memory (EEPROM). When the ECM is
replaced, the new ECM must be programmed. Refer to ECM Replacement and Programming Procedures Engine Control Module (ECM) and
Sensors.