Inspection Procedure 2

INSPECTION PROCEDURE 2: When Clutch Pedal is Depressed, Auto-cruise Control System is not Cancelled [M/T].













CIRCUIT OPERATION

This circuit judges the signals of clutch pedal position switch. The ECM detects the state of the clutch pedal position switch by sensing the voltages shown below.

- When the brake pedal is depressed (clutch pedal position switch are OFF): 0 - 0.3 volt.
- When the brake pedal is released (clutch pedal position switch are ON): 4.7 - 5.0 volts.

COMMENT

The clutch pedal position switch circuit is suspected.

TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CASE:)

- Malfunction of the clutch pedal position switch.
- Damaged harness or connector.
- Malfunction of the ECM.

DIAGNOSIS

Required Special Tools:

- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A
- MB991223: Harness Set
- MB992006: Extra Fine Probe
- MB991923: Power Plant ECU Check Harness

STEP 1. Using scan tool MB991958, check data list item 78: Clutch switch.





(1)
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 scan tool MB991958 to the data link connector. (Refer to Reading and Clearing Diagnostic Trouble Codes).
(2)Turn the ignition switch to the "ON" position.
(3)Set scan tool MB991958 to data reading mode for auto-cruise control system. (Refer to Scan Tool Testing and Procedures).

- Item 78: Clutch switch.
- When the clutch pedal is depressed, the display on scan tool MB991958 should be "ON".
- When the clutch pedal is released, the display on scan tool MB991958 should be "OFF".
(4)Turn the ignition switch to the "LOCK" (OFF) position.
(5)Disconnect scan tool MB991958.

Q. Is the switch operating properly?

YES Go to Step 7.

NO Go to Step 2.

STEP 2. Measure the terminal voltage at ECM connector B-18.





(1)Disconnect all the connectors from the ECM.





(2)Connect special tool MB991923 between the ECM and the body-side harness connector.
(3)Turn the ignition switch to the "ON" position.





(4)Measure the terminal voltage between special tool 18-pin connector terminal 16 (ECM connector B-18 terminal 16) and ground.

- When the clutch pedal is depressed, the measured voltage is between 4.7 and 5.0 volts.
- When the brake pedal is released, the measured voltage is between 0 and 0.3 volt.
(5)Turn the ignition switch to the "LOCK" (OFF) position.
(6)Disconnect special tool MB991923 between the ECM and the body-side harness connector.
(7)Reconnect all the connectors to the ECM.

Q. Is the measured voltage between 4.7 and 5.0 volts when the brake pedal is depressed and between 0 and 0.3 volt when the brake pedal is released?

YES Go to Step 7.

NO Go to Step 3.

STEP 3. Check ECM connector B-18 and clutch pedal position switch connector C-129 for loose, corroded or damaged terminals, or terminals pushed back in the connector.









Q. Are the connectors and terminals in good condition?

YES Go to Step 4.

NO Repair or replace the damaged components. Harness Connector Inspection). Then go to Step 8.

STEP 4. Check the harness wire between ECM connector B-18 terminal 16 and clutch pedal position switch connector C-129 terminal 2 for damage.









Q. Is the harness wire in good condition?

YES Go to Step 5.

NO Repair the damaged harness wire. Then go to Step 8.

STEP 5. Check the harness wire between clutch pedal position switch connector C-129 terminal 1 and ground for damage.









Q. Is the harness wire in good condition?

YES Go to Step 6.

NO Repair the damaged harness wire. Then go to Step 8.

STEP 6. Check the clutch pedal position switch.

(1)Remove the clutch pedal position switch. Removal and Installation).









(2)Connect an ohmmeter to the clutch pedal position switch between terminals 1 and 2.
(3)Check for continuity between the terminals when the plunger of the clutch pedal position switch is pushed in and when it is released.
(4)The clutch pedal position switch is operating properly if the circuit is open between terminals 1 and 2 when the plunger is pushed in to a depth of within 4.0 mm (0.16 inch) from the outer case edge surface, and if the resistance value is less than 2 ohms between terminals 1 and 2 when it is released.

Q. Is the clutch pedal position switch operating properly?

YES Install the clutch pedal position switch. Removal and Installation).
Then go to Step 7.

NO Replace the clutch pedal position switch. Removal and Installation).
Then go to Step 8.

STEP 7. Check the symptoms.

Q. When the clutch pedal is depressed, is auto-cruise control cancelled?

YES It can be assumed that this malfunction is intermittent. How to Cope With Intermittent Malfunctions).
NO Replace the ECM. Immobilizer System). Then go to Step 8.
STEP 8. Check the symptoms.

Q. When the clutch pedal is depressed, is auto-cruise control cancelled?

YES The procedure is complete.
NO Return to Step 1.