Diagnostic Item 14

DIAGNOSTIC ITEM 14: 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 maybe 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 convertible top control module and joint connector (3)]
- The connector may be defective [poor connection of joint connector (3) or convertible top control module connector]
- The convertible top control module 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
- MB991970: ABS Check Harness

STEP 1. Check joint connector (3) C-03 and convertible top control module connector D-45 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 convertible top control module connector D-45 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-23 and joint connector (3). Measure the resistance between intermediate connector C-23 and joint connector (3) C-03.

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




1. Disconnect intermediate connector C-23 and joint connector (3) C-03, and measure the resistance between the wiring harness side connector of joint connector (3) C-03 and the male side connector of intermediate connector C-23 (at front wiring harness side).
2. Turn the ignition switch to the "LOCK" (OFF) position.

CAUTION: Disconnect the negative battery terminal.

3. Disconnect the negative battery terminal.




4. Measure the resistance between intermediate connector C-23 (terminal 22) and joint connector (3) C-03 (terminal 9).

OK: 2 ohms or less




5. Measure the resistance between intermediate connector C-23 (terminal 23) 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 : If all the resistances measure 2 ohms or less, go to Step 3.

NO : If either of the resistances measures more than 2 ohms or all the resistances measure more than 2 ohms, repair the wiring harness between intermediate connector C-23 and the joint connector (3) C-03.

STEP 3. Check the CAN bus lines between intermediate connector C-23 and the convertible top control module connector D-45. Measure the resistance between intermediate connector C-23 and convertible top control module connector D-45.

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




1. Disconnect intermediate connector C-23 and convertible top control module connector D-45, and measure the resistance between the wiring harness side connector of convertible top control module connector D-45 and the male side connector of intermediate connector C-23 (at front wiring harness side).
2. Turn the ignition switch to the "LOCK" (OFF) position.

CAUTION: Disconnect the negative battery terminal.




3. Disconnect the negative battery terminal.




4. Measure the resistance between intermediate connector C-23 (terminal 22) and convertible top control module connector D-45 (terminal 48).

OK: 2 ohms or less




5. Measure the resistance between intermediate connector C-23 (terminal 23) and convertible top control module connector D-45 (terminal 49).

OK: 2 ohms or less

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

YES : If all the resistances measure 2 ohms or less, go to Step 4.

NO : If either of the resistances measures more than 2 ohms or all the resistances measure more than 2 ohms, repair the wiring harness between intermediate connector C-23 and the convertible top control module connector D-45.

STEP 4. Check the CAN bus lines inside the convertible top control module. Measure the resistance at convertible top control module connector D-45.




1. Disconnect convertible top control module connector D-45, and measure the resistance at the component side of convertible top control module connector D-45.




2. Measure the resistance between convertible top control module connector D-45 (terminals 48 and 37).

OK: 2 ohms or less




3. Measure the resistance between convertible top control module connector D-45 (terminals 49 and 38).

OK: 2 ohms or less

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

YES : Go to Step 5.

NO : Replace the convertible top control module.

STEP 5. 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 terminals 17 and 18.

OK: 120 ± 20 ohms

Q: Does the resistance measure 120 ± 20 ohms?

YES : Intermittent malfunction.

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. Refer to Chassis Electrical, Encrypted Code Registration Criteria Table.