Test Description

Number(s) below refer the step number(s) on the Diagnostic Chart:

1. 1. The Check Engine Lamp (MIL) should be ON steady with the ignition "On", engine "Off. If not, "No Check Engine Lamp (MIL)" chart should be used to isolate the malfunction.
2. 2. Checks the Class 2 data circuit and ensures that the ECM is able to transmit serial data.
3. 3. This test ensures that the ECM is capable of controlling the Check Engine Lamp (MIL) and the Check Engine Lamp (MIL) driver circuit is not shorted to ground circuit.
4. 4. If the engine will not start, "Engine Cranks But Will Not Run" chart should be used to diagnose the fault.
5. 6. The Tech 2 parameters which is not within the typical range may help to isolate the area which is causing the problem.
6. 12. This vehicle is equipped with ECM which utilizes an electrically erasable programmable read only memory (EEPROM).

Fig 1: Identifying Communication System Check Chart (1 Of 2)

Courtesy of ISUZU MOTOR CO.

Fig 2: Identifying Communication System Check Chart (2 Of 2)

Courtesy of ISUZU MOTOR CO.