Diagnostic Item 15

DIAGNOSTIC ITEM 15: Diagnose when the scan tool cannot receive the data sent by the ECM [M/T] or the PCM [A/T] and convertible top control module.[ECLIPSE SPYDER]

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.

Part 1:

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 convertible top control module" when the scan tool MB991958 checks the periodically sent data from each ECU and cannot receive convertible top control module and ECM [M/T] or powertrain control system [A/T] data only.

TROUBLE JUDGEMENT CONDITIONS
Scan tool MB991958 judges the trouble when the periodically sent data from convertible top control module and ECM [M/T] or PCM [A/T] cannot be received and sent.

TROUBLESHOOTING HINTS
- The wiring harness may be defective (open circuit between ABS-ECU [vehicles without TCL or ASC] or ABS/TCL-ECU [vehicles with TCL] or TCL/ASC-ECU [vehicles with ASC] and ECM [M/T] or PCM [A/T])
- The connector may be defective (poor connection of ECM [M/T] or PCM [A/T] connector and ABS-ECU [vehicles without TCL or ASC] or ABS/TCL-ECU [vehicles with TCL] or TCL/ASC-ECU [vehicles with ASC] connector)
- Power supply circuit malfunction of the ECM [M/T] or PCM [A/T]
- The ABS-ECU [vehicles without TCL or ASC] or ABS/TCL-ECU [vehicles with TCL] or TCL/ASC-ECU [vehicles with ASC] may be defective (internal open circuit) " The ECM [M/T] or PCM [A/T] may be defective
- The ECM [M/T] or PCM [A/T] may be defective (internal open circuit)
- Power supply circuit malfunction of convertible top control module

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra fine probe
- MB991923: Power plant ECU Check Harness
- MB991974: ABS Check Harness
- MB991997: ASC Check Harness

STEP 1. Check ABS-ECU connector A-02 [vehicles without TCL or ASC] or ABS/TCL-ECU connector A-03 [vehicles with TCL] or TCL/ASC-ECU connector A-38 [vehicles with ASC] and ECM connector [M/T] or PCM connector [A/T] B-18 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 ABS-ECU connector A-02 [vehicles without TCL or ASC] or ABS/TCL-ECU connector A-03 [vehicles with TCL] or TCL/ASC-ECU connector A-38 [vehicles with ASC] and ECM connector [M/T] or PCM connector [A/T] B-18 in good condition?

YES : Go to Step 2.

NO : Repair the damaged parts. Then go to Step 5.

STEP 2. Check the CAN bus lines between the ABS-ECU [vehicles without TCL or ASC] or ABS/TCL-ECU [vehicles with TCL] or TCL/ASC-ECU [vehicles with ASC] and the ECM [M/T] or PCM [A/T]. Measure the resistance between ABS-ECU connector A-02 [vehicles with traction control system] or ABS/TCL-ECU connector [vehicles with traction control system] and ECM connector [M/T] or PCM connector [A/T] B-18.

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















1. Disconnect ABS-ECU connector A-02 [vehicles without TCL or ASC] or ABS/TCL-ECU connector A-03 [vehicles with TCL] or TCL/ASC-ECU connector A-38 [vehicles with ASC] and ECM [M/T] or PCM connector [A/T] B-18, and measure the resistance between each wiring harness side connector.







2. Measure the resistance between ABS-ECU connector [vehicles without TCL or ASC] A-02 (terminal 4) and ECM connector [M/T] or PCM connector [A/T] B-18 (terminal 17).

OK: 2 ohms or less







3. Measure the resistance between ABS-ECU connector [vehicles without TCL or ASC] A-02 (terminal 6) and ECM connector [M/T] or PCM connector [A/T] B-18 (terminal 18).

OK: 2 ohms or less







4. Measure the resistance between ABS/TCL-ECU connector [vehicles with TCL] A-03 (terminal 11) and ECM connector [M/T] or PCM connector [A/T] B-18 (terminal 17).

OK: 2 ohms or less







5. Measure the resistance between ABS/TCL-ECU connector [vehicles with traction control system] A-03 (terminal 15) and ECM connector [M/T] or PCM connector [A/T] B-18 (terminal 18).

OK: 2 ohms or less







6. Measure the resistance between TCL/ASC-ECU connector [vehicles with ASC] A-38 (terminal 11) and ECM connector [M/T] or PCM connector [A/T] B-18 (terminal 17).

OK: 2 ohms or less







7. Measure the resistance between TCL/ASC-ECU connector [vehicles with ASC] A-38 (terminal 15) and ECM connector [M/T] or PCM connector [A/T] B-18 (terminal 18).

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 the ABS-ECU [vehicles without TCL or ASC] connector A-02 or ABS/TCL-ECU [vehicles with TCL] connector A-03 or TCL/ASC-ECU [vehicles with ASC] connector A-38 and the ECM connector [M/T] or PCM connector [A/T] B-18. Then go to Step 5.

STEP 3. Check the CAN bus lines inside the ABS-ECU [vehicles without TCL or ASC] or ABS/TCL-ECU [vehicles with TCL] or TCL/ASC-ECU [vehicles with ASC]. Measure the resistance at ABS-ECU connector A-02 [vehicles without TCL or ASC] or ABS/TCL-ECU connector A-03 [vehicles with TCL] or TCL/ASC-ECU connector A-38 [vehicles with ASC].







1. Disconnect ABS-ECU connector A-02 [vehicles without TCL or ASC] or ABS/TCL-ECU A-03 [vehicles with TCL] or TCL/ASC-ECU A-38 [vehicles with ASC], and measure the resistance at the component side of ABS-ECU connector A-02 [vehicles without TCL or ASC] or ABS/TCL-ECU connector A-03 [vehicles with TCL] or TCL/ASC-ECU connector A-38 [vehicles with ASC].







2. Measure the resistance between ABS-ECU [vehicles without TCL or ASC] connector A-02 (terminals 2 and 4).

OK: 2 ohms or less







3. Measure the resistance between ABS-ECU [vehicles without TCL or ASC] connector A-02 (terminals 8 and 6).

OK: 2 ohms or less







4. Measure the resistance between ABS/TCL-ECU [vehicles with TCL] connector A-03 (terminals 11 and 27).

OK: 2 ohms or less







5. Measure the resistance between ABS/TCL-ECU [vehicles with TCL] connector A-03 (terminals 13 and 15).

OK: 2 ohms or less







6. Measure the resistance between TCL/ASC-ECU [vehicles with ASC] connector A-38 (terminals 11 and 27).

OK: 2 ohms or less







7. Measure the resistance between TCL/ASC-ECU [vehicles with ASC] connector A-38 (terminals 13 and 15).

OK: 2 ohms or less

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

YES : Go to Step 4.

NO : Replace the ABS-ECU [vehicles without TCL or ASC] or ABS/TCL-ECU [vehicles with TCL] or TCL/ASC-ECU [vehicles with ASC]. Then go to Step 5.

STEP 4. Check the terminator resistor inside the ECM [M/T] or PCM [A/T]. Measure the resistance at ECM [M/T] or PCM [A/T] connector B-18.







1. Disconnect ECM [M/T] or PCM [A/T] connector B-18, and measure the resistance at the component side of ECM [M/T] or PCM [A/T] connector B-18.







2. Measure the resistance between ECM [M/T] or PCM [A/T] connector B-18 (terminals 17 and 18).

OK: 120 ± 20 ohms

Q: Does the resistance measure 120 ± 20 ohms?

YES : Diagnose the engine. Refer to MFI diagnosis [2.4L engine] or [3.8L engine]. Inspection Procedure 1 Then go to Step 5.

NO : Replace the ECM [M/T] or PCM [A/T]. When the ECM [M/T] or PCM [A/T] is replaced, register the encrypted code. Then go to Step 5.

STEP 5. Retest the system.

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.







1. Connect scan tool MB991958 to the data link connector.







2. Diagnose CAN bus lines, and check if scan tool MB991958 screen is as shown in the illustration.

Q: Does scan tool MB991958 screen correspond to the illustration?

YES : Diagnose the convertible top control system. Refer to Convertible top diagnosis. Roof and Associated Components

NO : Return to Step 1.