Eclipse L4-1997cc 2.0L DOHC (1991)
Engine Control Module: Component Tests and General Diagnostics
Detailed Component Locations - Electronic Control Unit
To test the Electronic Control Unit (ECU), located in front of the center console, proceed as follows:
NOTE: Diagnostic memory is erased if the battery or the ECU connector is disconnected. Do not disconnect the battery before the trouble codes
are completely read.
NOTE: If a sensor connector is disconnected with the ignition switch turned on, the diagnosis code is memorized. In this case, disconnect the
battery negative terminal for 15 seconds or more, and all diagnostic memory will be erased.
1.
Using the testing procedures extract all malfunction codes.
Diagnosis memory is erased if the battery or the ECU connector is disconnected. Do not disconnect the battery before the trouble codes are
completely read.
CAUTION: When battery Voltage is low, trouble codes cannot be read. Be sure to check the battery for Voltage and other conditions before
starting the test.
2.
Does the ECU output a steady 12 VDC at the check connector?
a. If not, and the ECU is suspected to be faulty Test to confirm that the ECU is being supplied with power and ground.
b. If so replacement of the ECU is required.
