Inspection Procedure 5: Speedometer does not Work (Other Meters Work).

COMMENTS ON TROUBLE SYMPTOM

If only the speedometer does not operate, the engine ECU system, the combination meter, the wiring harness or its connector may be defective. Furthermore, incorrect level of fuel is shown on the gauge, because the display unit can not learn the fuel gauge.

PROBABLE CAUSES

Damaged harness wires and connectors
Malfunction of vehicle speed sensor
Malfunction of engine ECU
Malfunction of combination meter

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III other system diagnosis code.

Check whether the DIESEL system-related diagnosis code is set.

Q. Is the diagnosis code set?

	Diagnose DIESEL system. (Refer to GROUP 13A, Troubleshooting .) After diagnosing the DIESEL system, go to Step 5.

	Go to Step 2.

STEP 2. M.U.T.-III other system data list

Check the vehicle speed signal data list of DIESEL system.

Item No.4: Vehicle speed sensor (Refer to GROUP 13A, Data list reference table

Q. Is the check result satisfactory?

	Go to Step 3.

	Diagnose DIESEL system. (Refer to GROUP 13A, Troubleshooting .) After diagnosing the DIESEL system.

STEP 3. Connector check: Joint connector C-127 and combination meter connector C-112.

Q. Is joint connector C-127 and combination meter connector C-112 in good condition?

Go to Step 4.

Repair or replace the damage component(s).

STEP 4. Check the wiring harness between joint connector C-127 (terminal 19) and combination meter connector C-112 (terminal 35).

Q. Is the wiring harness between joint connector C-127 (terminal 19) and combination meter connector C-112 (terminal 35) in good condition?

Go to Step 5.

Repair or replace the damage component(s).

STEP 5. Retest the system.

Q. Is the speedometer normal?

	The procedure is complete. (If no malfunctions are found in all steps, an intermittent malfunction is suspected. Refer to GROUP 00 / How to Cope with Intermittent Malfunction ).

	Go to Step 6.

STEP 6. Pulse check

Use the M.U.T.-III or a voltmeter to check that the vehicle speed signal is received.

note

Drive the vehicle with the M.U.T.-III connected to the diagnosis connector. The M.U.T.-III buzzer should sound.

System switch	Check conditions
Vehicle speed signal	When the vehicle speed has reached 10 km/h or more

OK: The M.U.T.-III sounds or the voltmeter needle fluctuates.

Q. Is the check result normal?

	Replace the combination meter assembly.

	Replace the engine-ECU. Perform the Chassis No. Writing after the engine-ECU is replaced.(Refer to GROUP 00, How to perform chassis number (Chassis No.) writing )