Engine Control Module: Testing and Inspection

ECU Power Supply And Ground Circuit:

NOTE: Never connect or disconnect the control unit or any sensors with the ignition "ON" unless specifically instructed to do so by a test procedure. Failure to follow this precaution could result in damage to electronic components.

While there is no specific test for the ECU, nor does it set a trouble code if a fault occurs in its own circuitry, many of the component tests lead to the ECU if no other problems are detected.

ECU Power Supply Testing:

ECU POWER SUPPLY

1. Turn ignition switch "ON."
2. Measure voltage between ECU connector terminals and ground on vehicle body. Specified voltages and connector terminals are listed in the image table.

ECU Ground Circuit Testing:

ECU GROUNDING CIRCUIT

1. Turn ignition switch "OFF."
2. Measure resistance between ECU connector terminals and body. Specified resistances and connector terminals are listed in the image table.

ECU Connector Table (a):

ECU Connector Table (b):

ECU CONNECTOR TABLE

Wire color code identification:

L: Blue
B: Black
Y: Yellow
G: Green
R: Red
W: White
Br: Brown
Lg: Light green
Gr: Gray