A - Charts

ETACS-ECU Power Supply And Scan Tool Communication Circuit:

Connectors:

CIRCUIT OPERATION
The ETACS-ECU receives a diagnostic trouble code and switch signals from the data link connector.

TECHNICAL DESCRIPTION (COMMENT)
The harness wires between the ETACS-ECU power supply line or the ETACS-ECU and the data link connector may be defective.

TROUBLESHOOTING HINTS
- Malfunction of the ETACS-ECU
- Damaged harness wires or connectors

DIAGNOSIS
Required Special Tools:
MB991223: Harness Set
MB991502: Scan Tool (MUT-II)
MB991529: Diagnostic Trouble Code Check Harness

STEP 1. Check the communication with other systems.
If the scan tool can not communicate with all systems, refer to Diagnosis (Computers/Testing).
If the scan tool can not communicate with the SWS only, go to Step 2.

STEP 2. Check the ignition switch positions.
If scan tool MB991502 can communicate with the ETACS-ECU with the ignition switch at "ON" position, check the ETACS-ECU battery circuits. Refer to Inspection Procedure P-1.
P - Charts

If scan tool MB991502 can communicate with the ETACS-ECU regardless of the ignition switch position, go to Step 3.







STEP 3. Check data link connector C-29 and ETACS-ECU connector C-111 for damage.
If data link connector C-29 and ETACS-ECU connector C-111 are damaged, repair or replace them. Refer to Harness Connector Inspection.
Scan tool MB991502 should communicate with the SRS.

If the connectors are in good condition, go to Step 4.










STEP 4. Check the harness wires between data link connector C-29 and ETACS-ECU connector C-111.

NOTE: After checking joint connector C-77, check the wires. If joint connector C-77 is damaged, repair or replace it. Refer to Harness Connector Inspection.

If the harness wires between data link connector C-29 and ETACS-ECU connector C-111 are damaged, repair them.
Scan tool MB991502 should communicate with the SWS.

If the harness wires are in good condition, go to Step 5.




STEP 5. Check the ETACS-ECU ground circuit at the ETACS-ECU connector C-114.
1. Disconnect the ETACS-ECU connector C-114 and measure at the junction block side.
2. Resistance between terminal 1 and ground.
- Should be less than 2 Ohms.
If open circuit, go to Step 6.
If less than 2 Ohms. replace the ETACS-ECU.
Scan tool MB991502 should communicate with the SWS.




STEP 6. Check the ETACS-ECU connector C-114 for damage.
If the ETACS-ECU connector C-114 is damaged, repair or replace it. Refer to Harness Connector Inspection.

If the connector is in good condition, go to Step 7.







STEP 7. Check the harness wires between ETACS-ECU connector C-114 and ground.

NOTE: After checking junction block connector C-101, check the wires. If junction block connector C-101 is damaged, repair or replace it. Refer to Harness Connector Inspection.

If the harness wires between ETACS-ECU connector C-114 and ground are damaged, repair them.
Scan tool MB991502 should communicate with the SWS.