Diagnostic Item 13

DIAGNOSTIC ITEM 13: Diagnose when the scan tool cannot receive the data sent by the ECM [M/T] or the PCM [A/T] and TCL/ASC-ECU. [ECLIPSE]

CAUTION: When servicing a CAN bus line, ground yourself by touching a metal object such as an unpainted water pipe. If you fail to do so, a component connected to the CAN bus line may be damaged.

Eclipse (Part 1):

Eclipse (Part 2):

FUNCTION
The diagnostic result demonstrates that "the scan tool cannot receive the sent data from the ECM [M/T] or PCM [A/T] and TCL/ASC-ECU" when the scan tool MB991958 checks the periodically sent data from each ECU and cannot receive TCL/ASC-ECU and ECM [M/T] or PCM [A/T] data only.

TROUBLE JUDGEMENT CONDITIONS
Scan tool MB991958 judges the trouble when the periodically sent data from TCL/ASC-ECU and ECM [M/T] or PCM [A/T] cannot be received and sent.

TROUBLESHOOTING HINTS
- The wiring harness may be defective [open circuit between TCL/ASC-ECU and joint connector (3) or open circuit between TCL/ASC-ECU and ECM [M/T] or PCM [A/T]
- The connector may be defective [poor connection of joint connector (3) or TCL/ASC-ECU connector]
- The TCL/ASC-ECU may be defective (internal open circuit)
- The ECM [M/T] or PCM [A/T] may be defective (internal open circuit)

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra fine probe
- MB991923: Power plant ECU Check Harness
- MB991997: ASC Check Harness

STEP 1. Check joint connector (3) C-03 and TCL/ASC-ECU connector A-38 for loose, corroded or damaged terminals, or terminals pushed back in the connector.










CAUTION: The strand end of the twisted wire should be within 10 cm (4.0 inches) from the connector.

Q: Are joint connector (3) C-03 and TCL/ASC-ECU connector A-38 in good condition?

YES : Go to Step 2.

NO : Repair the damaged parts. Replace the joint connector as necessary.







STEP 2. Check the CAN bus lines between intermediate connector C-24 and joint connector (3). Measure the resistance between intermediate connector C-24 and joint connector (3) C-03.

CAUTION:
- A digital multimeter should be used.
- The test wiring harness should be used.

1. Turn the ignition switch to the "LOCK" (OFF) position.

CAUTION: Disconnect the negative battery terminal.

2. Disconnect the negative battery terminal.







3. Disconnect intermediate connector C-24 and joint connector (3) C-03, and measure the resistance between the wiring harness side connector of joint connector (3) C-03 and the female side connector of intermediate connector C-24 (at instrument panel wiring harness side).







4. Measure the resistance between intermediate connector C-24 (terminal 11) and joint connector (3) C-03 (terminal 9).

OK: 2 ohms or less







5. Measure the resistance between intermediate connector C-24 (terminal 12) and joint connector (3) C-03 (terminal 20).

OK: 2 ohms or less

CAUTION: Strictly observe the specified wiring harness repair procedure.

Q: Do all the resistances measure 2 ohms or less?

YES : Go to Step 3.

NO : Repair the wiring harness between intermediate connector C-24 and the joint connector (3) C-03.

STEP 3. Check the CAN bus lines between intermediate connector C-24 and the TCL/ASC-ECU. Measure the resistance between intermediate connector C-24 and TCL/ASC-ECU connector A-38.

CAUTION:
- A digital multimeter should be used.
- The test wiring harness should be used.

1. Turn the ignition switch to the "LOCK" (OFF) position.

CAUTION: Disconnect the negative battery terminal.

2. Disconnect the negative battery terminal.










3. Disconnect intermediate connector C-24 and TCL/ASC-ECU connector A-38, and measure the resistance between the wiring harness side connector of TCL/ASC-ECU connector A-38 and the male side connector of intermediate connector C-24 (at front wiring harness side).







4. Measure the resistance between intermediate connector C-24 (terminal 11) and TCL/ASC-ECU connector A-38 (terminal 27).

OK: 2 ohms or less







5. Measure the resistance between intermediate connector C-24 (terminal 12) and TCL/ASC-ECU connector A-38 (terminal 13).

OK: 2 ohms or less

CAUTION: Strictly observe the specified wiring harness repair procedure.

Q: Do all the resistances measure 2 ohms or less?

YES : Go to Step 4.

NO : Repair the wiring harness between intermediate connector C-24 and the TCL/ASC-ECU connector A-38.

STEP 4. Check the CAN bus lines inside the TCL/ASC-ECU. Measure the resistance at TCL/ASC-ECU connector A-38.







1. Disconnect TCL/ASC-ECU A-38, and measure the resistance at the component side of TCL/ASC-ECU connector A-38.







2. Measure the resistance between TCL/ASC-ECU connector A-38 (terminals 11 and 27).

OK: 2 ohms or less







3. Measure the resistance between TCL/ASC-ECU connector A-38 (terminals 13 and 15).

OK: 2 ohms or less

Q: Do all the resistances measure 2 ohms or less?

YES : Intermittent malfunction.

NO : Replace the TCL/ASC-ECU.