Lancer L4-2.4L SOHC (2005)
Front-ECU Power Supply And SWS Communication Circuit Part 2
CIRCUIT OPERATION
-
The power supply to the front-ECU is provided by the battery and the ignition switch (IG2).
-
If the power supply system from the battery is defective, the system operates by the power supply from the ignition switch (IG2).
TECHNICAL DESCRIPTION (COMMENT)
It is suspected that the power supply circuit to the front-ECU is defective, or the wiring harness between the SWS monitor kit and the front-ECU or their
connector(s) is damaged. If the battery power supply circuit to the ECU (terminal 7 of the front-ECU) is damaged, also check the power supply circuit
from the ignition switch (IG2) (terminal 30 of the front-ECU), and repair if necessary.
TROUBLESHOOTING HINTS
-
The ETACS-ECU may be defective
-
The front-ECU may be defective
-
The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
DIAGNOSIS
Required Special Tools:
-
MB991223: Harness Set
-
MB991958: Scan Tool (MUT-III Sub Assembly)
-
MB991824: Vehicle Communication Interface (V.C.I.)
-
MB991827: MUT-III USB Cable
-
MB991911: MUT-III Main Harness B
-
MB991813: SWS Monitor Kit
-
MB991806: SWS Monitor Cartridge
-
MB991812: SWS Monitor Harness (For Column-ECU)
-
MB991922: Probe Harness
STEP 1. Use scan tool MB991958 to select "ECU COMM CHK" on the SWS monitor display. Check the ETACS-ECU.
CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or
disconnecting scan tool MB991958. Connect the DLC harness before connecting the column-ECU harness. Be sure to connect SWS monitor kit
MB991813 after turning on scan tool MB991958.
