Inspection Procedure 8
INSPECTION PROCEDURE 8: Tachometer does not Work.
CIRCUIT OPERATION
The powertrain control module sends ignition signal to the combination meter via CAN bus line.
TECHNICAL DESCRIPTION (COMMENT)
If only the tachometer does not operate, the powertrain control module system may not be sending ignition signal, or the combination meter, the wiring harness or its connector may be defective.
TROUBLESHOOTING HINTS
- Malfunction of the combination meter
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
DIAGNOSIS
Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A (Vehicles with CAN communication system)
STEP 1. Using scan tool MB991958, diagnose the CAN bus line.
(1)Connect scan tool MB991958 to the data link connector.
(2)Turn the ignition switch to "ON" position.
(3)Diagnose the CAN bus line.
Q. Is the check result satisfactory?
YES Go to Step 2.
NO Repair the CAN bus lines CAN Bus Diagnostics Chart).
On completion, go to Step 3.
STEP 2. Using scan tool MB991958, read MFI system diagnostic trouble code.
Check if the MFI system DTC is set.
Q. Is the DTC set?
YES Diagnose the MFI system Multiport Fuel Injection (MFI) [2.4L ENGINE]. On completion, go to Step 5.
NO Go to Step 3.
STEP 3. Using scan tool MB991958, check data list.
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)Turn the ignition switch to the "ON" position.
(3)Set scan tool MB991958 to the data reading mode.
- Item 87: Tachometer
- Tachometer displayed value and scan tool MB991958 displayed value agree with each other.
(4)Turn the ignition switch to the "LOCK" (OFF) position.
Q. Is the check result normally?
YES It can be assumed that this malfunction is intermittent. How to Cope With Intermittent Malfunctions.
NO Go to Step 4.
STEP 4. Using scan tool MB991958, check actuator test.
(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.
(2)Turn the ignition switch to the "ON" position.
(3)Set scan tool MB991958 to the actuator test mode.
- Item 84: Tachometer: 0 r/min
- The tachometer displays 0 r/min.
- Item 85: Tachometer: 2000 r/min
- The tachometer displays 2,000 r/min.
- Item 86: Tachometer: 5000 r/min
- The tachometer displays 5,000 r/min.
(4)Turn the ignition switch to the "LOCK" (OFF) position.
Q. Is the check result normally?
YES Go to Step 5.
NO Replace the combination meter.
STEP 5. Retest the system.
Check that the tachometer works normally.
Q. Is the check result satisfactory?
YES The procedure is complete. (If no malfunctions are found in all steps, an intermittent malfunction is suspected. How to Cope With Intermittent Malfunctions).
NO Replace the combination meter.