Inspection Procedure 3

Tachometer does not Work.

Tachometer Circuit Part 1:

Tachometer Circuit Part 2:

CIRCUIT OPERATION
- The tachometer power is supplied from the ignition switch (IG) circuit.
- The tachometer calculates the engine revolution (r/min) according to the ECM or PCM signals to operate the needle.

TECHNICAL DESCRIPTION (COMMENT)
The cause is thought to be because ECM or PCM signals are not transmitted or due to combination meter error.

TROUBLESHOOTING HINTS
- Malfunction of the combination meter (printed circuit board or speedometer and tachometer)
- Malfunction of the ECM or PCM
- Damaged wiring harness or connectors

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB991502: Scan Tool (MUT-II)

STEP 1. Check with other meter.

Check to see that the speedometer, fuel gauge and water thermometer operate normally.

Q: Do all other meters operate?

YES< other meters all operate >. : Go to Step 2.

NO< one of the meters do not operate >. : Refer to INSPECTION PROCEDURE 5.

STEP 2. Using scan tool MB991502, read the diagnostic trouble code (DTC).

CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to "LOCK" (OFF) position before connecting or disconnecting scan tool.

1. Connect scan tool MB991502 to the data link connector.
2. Turn the ignition switch to "ON" position.
3. Read the MFI system diagnostic trouble code.

Q: Is DTC output to the MFI system?

YES: Refer to Group 13-Multiport Fuel Injection (MFI) Diagnosis.

NO: Go to Step 3.

STEP 3. Check combination meter connector C-01 and ECM connector C-117 or PCM connector C-118 for damage.

Q: Are combination meter connector C-01 and ECM connector C-117 or PCM connector C-118 in good condition?

YES: Go to Step 4.

NO: Repair or replace the connector. Refer to Harness Connector Inspection. The tachometer should work normally.

STEP 4. Check the wiring harness between combination meter connector C-01 (terminal 11) and ECM connector C-117 (terminal 58) or PCM connector C-118 (terminal 43).

Q: Are the wiring harness between combination meter connector C-01 (terminal 11) and ECM connector C-117 (terminal 58) or PCM connector C-118 (terminal 43) in good condition?

YES: Go to Step 5.

NO: Repair the wiring harness. The tachometer should work normally.

STEP 5. Replace the combination meter and check.

Q: Does the tachometer operate?

YES: There is no action to be taken.

NO: Replace the PCM. The tachometer should work normally.