Test Mil - Malfunction Indicator Light
1) Check System Integrity Visually check all wiring, connectors and components for evidence of damage, shorting or looseness. If fault is found, repair as necessary. If no fault is found, go to next step.
2) Check MIL Operation Turn ignition off. Install breakout box, leaving PCM disconnected. Turn ignition on. Ground MIL test pin (No. 51) at breakout box. If MIL is on, MIL circuit is okay. If codes do not flash on MIL during QUICK TEST or MIL never comes on, replace PCM. If MIL is off, go to next step.
3) Check MIL Bulb Turn ignition off. Remove instrument cluster. Remove and inspect MIL bulb. Replace bulb as necessary. If bulb is okay, go to next step.
4) Check For Open MIL Wire Turn ignition off. Disconnect instrument cluster connector. Ensure ignition is off, breakout box is installed and PCM is disconnected. Measure resistance between MIL test pin (No. 31) at breakout box and MIL terminal at instrument cluster connector. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in MIL wire.
5) Check For Short In MIL Wire Ensure ignition is off, breakout box is installed and PCM and instrument cluster connectors are disconnected. Measure resistance between ground and MIL test pin (No. 51) at breakout box. If resistance is more than 10,000 ohms, replace instrument cluster printed circuit board. If resistance is 10,000 ohms or less, repair short to ground in MIL wire.