INSPECTION PROCEDURE 2: Tachometer does not Work.: Diagnosis

Required Special Tools:

MB991223: Harness Set
MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicles Communication Interface (V.C.I.)
- MB991827: MUT-III USB Cable
- MB991911: MUT-III Main Harness B (Vehicles without CAN communication system)

STEP 1. Using scan tool MB991958, read MFI system diagnostic trouble code.
Check if the MFI system DTC is set.

Fig 1: Connecting Scan Tool To Data Link Connector
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Q: Is MFI system DTC P0300 output?
1. YES: Check the MFI system, Go to Step 9.
2. NO: Go to Step 2.
STEP 2. Check the speedometer operation.
Q: Does the speedometer work normally?
1. YES: Refer to INSPECTION PROCEDURE 1 .
2. NO: Go to Step 3.
STEP 3. Check the combination meter (tachometer) ground circuit at the combination meter connector C-42.
1. Disconnect the combination meter connector C-42.
  
  Fig 2: Disconnecting Combination Meter Connector C-42
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. Measure the resistance between terminal 28 and ground.
  - The measured value should be 2 ohm or less.
Q: Does the measured resistance value correspond with this range?
1. YES: Go to Step 6.
2. NO: Go to Step 4.
STEP 4. Check the combination meter connector C-42 for damage.

Fig 4: Checking Combination Meter Connector C-42 For Damage
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Q: Is combination meter connector C-42 in good condition?
1. YES: Go to Step 5.
2. NO: Repair or replace the connector. Refer to HARNESS CONNECTOR INSPECTION . The tachometer should work normally.
STEP 5. Check the wiring harness between combination meter connector C-42 (terminal 28) and ground.

Fig 5: Identifying C-42 Connector Terminals
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Q: Is the wiring harness between combination meter connector C-42 (terminal 28) and ground in good condition?
1. YES: There is no action to be taken.
2. NO: Repair or replace the connector. The tachometer should work normally.
STEP 6. Check the ignition signal input circuit at the combination meter connector C-42.
1. Disconnect the combination meter connector C-42.
  
  Fig 6: Disconnecting Combination Meter Connector C-42
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. Start the engine and run at idle.
3. Measure the voltage between terminal 33 and ground.
  - The measured value should be between approximately 10 and 12 volts.
4. Check that the voltage drops below the standard value.
Q: Does the measured voltage correspond with this range?
1. YES: Repair or replace the combination meter (printed-circuit board or speedometer and tachometer).
2. NO: Go to Step 7.
STEP 7. Check the ECM connector C-56 <2.4L M/T> or PCM connector C-54 <2.4L A/T>, distributor assembly connector B-22 <3.0L engine>, automatic compressor controller connector C-13 <3.0L engine> and combination meter connector C-42 for damage.

Fig 8: Identifying C-54 And C-56 Connectors Terminals
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Fig 9: Identifying B-22 Connector Terminals
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Fig 10: Identifying C-13 Connector Terminals
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Fig 11: Identifying C-42 Connector Terminals
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Q: Are ECM connector C-56 <2.4L M/T> or PCM connector C-54 <2.4L A/T>, distributor assembly connector B-22 <3.0L engine>, automatic compressor controller connector C-13 <3.0L engine> and combination meter connector C-42 in good condition?
1. YES: Go to Step 8.
2. NO: Repair or replace the connector. Refer to HARNESS CONNECTOR INSPECTION . The tachometer should work normally.
STEP 8. Check the wiring harness from combination meter connector C-42 (terminal 33) to ECM connector C-56 (terminal 58) <2.4L M/T> or PCM connector C-54 (terminal 43) <2.4L A/T>, distributor assembly connector B-22 (terminal 2) <3.0L engine> and automatic compressor controller connector C-13 (terminal 22) <3.0L engine>.

Fig 12: Identifying C-54 And C-56 Connectors Terminals
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Fig 13: Identifying B-22 Connector Terminals
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Fig 14: Identifying C-13 Connector Terminals
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Fig 15: Identifying C-42 Connector Location
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NOTE: After checking intermediate connector C-28, check the wires. If intermediate connector C-28 is damaged, repair or replace it. Refer to HARNESS CONNECTOR INSPECTION .

Fig 16: Identifying C-28 Connector Terminals
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Q: Are the wiring harness from combination meter connector C-42 (terminal 33) to ECM connector C-56 (terminal 58) <2.4L M/T> or PCM connector C-54 (terminal 43) <2.4L A/T>, distributor assembly connector B-22 (terminal 2) <3.0L engine> and automatic compressor controller connector C-13 (terminal 22) <3.0L engine> in good condition?
1. YES: There is no action to be taken.
2. NO: Repair or replace the connector. The tachometer should work normally.
STEP 9. Using scan tool MB991958, check data list item 21: Crankshaft Position Sensor.
1. Start the engine and run at idle.
2. Set scan tool MB991958 to the data reading mode for item 21, Crankshaft Position Sensor.
  
  Fig 17: Identifying Data Link Connector Location
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
3. Check the waveform of the crankshaft position sensor while keeping the engine speed constant.
  - The pulse width should be constant.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?
1. YES: Go to Step 10.
2. NO: Refer to DTC P0335: CRANKSHAFT POSITION SENSOR CIRCUIT or DTC P0335: CRANKSHAFT POSITION SENSOR CIRCUIT .
STEP 10. Using scan tool MB991958, check data list item 81, 83 <3.0L>: Long - Term Fuel Compensation (trim).
1. Start the engine and run at idle.
2. Set scan tool MB991502 to the data reading mode for item 81, 83 <3.0L>: Long - Term Fuel Compensation (trim).
  - The fuel trim should be between - 12.5 and +12.5 % when the load is 2,500 r/min (during closed loop) after the engine is warmed.
3. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the specification normal?
1. YES: Go to Step 11.
2. NO: Refer to DTC P0171: SYSTEM TOO LEAN or DTC P0171: SYSTEM TOO LEAN (BANK 1) .
STEP 11. Using scan tool MB991958, check data list item 82, 84 <3.0L>: Short - Term Fuel Compensation (trim).
1. Start the engine and run at idle.
2. Set scan tool MB991958 to the data reading mode for item 82, 84 <3.0L>: Short - Term Fuel Compensation (trim).
  - The fuel trim should be between -25 and +16.8 % when the load is 2,500 r/min (during closed loop) after the engine is warmed.
3. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the specification normal?
1. YES: Go to Step 12.
2. NO: Refer to DTC P0171: SYSTEM TOO LEAN or DTC P0171: SYSTEM TOO LEAN (BANK 1) .
STEP 12. Check the ignition coil spark
1. Check each ignition coil spark.
2. Remove the intake manifold.
3. Remove the spark plug and connect to the spark plug cable.
  
  Fig 20: Removing Spark Plug
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
4. Ground the spark plug side electrode securely.
  - When the engine is cranked, the spark plug should spark.
Q: Did it spark?
1. YES: Go to Step 15.
2. NO: Go to Step 13.
STEP 13. Check the spark plugs.
CAUTION: Do not attempt to adjust the gap of the platinum plug. Cleaning of the platinum plug may result in damage to the platinum tips. Therefore, if carbon deposits must be removed, use a plug cleaner and complete cleaning within 20 seconds to protect the electrode. Do not use a wire brush.
1. Check the plug gap and replace if the limit is exceeded.
  1. Standard value: 1.0 - 1.1 mm (0.039 - 0.043 inch)
  2. Limit: 1.3 mm (0.051 inch)
Q: Is the plug gap at the standard value?
1. YES: Go to Step 14.
2. NO: Replace the faulty spark plug. Then go to Step 1
STEP 14. Check the spark plug cable.
1. Check the cap and coating for cracks.
  
  Fig 22: Checking Spark Plug Cable
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. Measure the resistance.
  1. Limit: maximum 22 kΩ
Q: Is the resistance normal?
1. YES: Refer to INSPECTION PROCEDURE 33: IGNITION CIRCUIT SYSTEM or INSPECTION PROCEDURE 33: IGNITION CIRCUIT SYSTEM .
2. NO: Replace the faulty spark plug cable. Then go to Step 1.
STEP 15. Check the injector.
1. Disconnect the injector connector.
2. Measure the resistance between each injector side connector terminal 1 and 2.
  - The measured value should be between approximately 13 and 16 ohm [at20°C (68°F)].
    
    Fig 23: Measuring Resistance Between Injector Side Connector Terminal 1 And 2
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Q: Does the measured voltage correspond with this range?
1. YES: Go to Step 16.
2. NO: Replace the faulty injector. Then go to Step 1.
STEP 16. Check connector at injector for damage.
Q: Is the connector in good condition?
1. YES:
  - Go to Step 17 <2.4L engine>.
  - Go to Step 2 <3.0L engine>.
2. NO: Repair or replace the faulty injector. Refer to HARNESS CONNECTOR INSPECTION . Then go to Step 1.
STEP 17. Check connector C-49 at ECM < M/T > or connector C-50 at PCM < A/T > and ignition coil connector B-16 and B-21 for damage <2.4L engine>.

Fig 24: Identifying C-49 And C-50 Connectors Terminals
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Fig 25: Identifying B-16 And B-21 Connectors Location
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Q: Is the connector in good condition?
1. YES: Go to Step 18.
2. NO: Refer to DIAGNOSTIC TROUBLE CODE CHART .
STEP 18. Check for harness damage between ignition coil B-16 (terminal 3), B-21 (terminal 3) and ECM connector C-49 (terminal 10 and 23) < M/T > or PCM connector C-50 (terminal 11 or 12) < A/T >.

Fig 26: Identifying B-16 And B-21 Connectors Terminals
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

Fig 27: Identifying C-49 And C-50 Connectors Terminals
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Q: Is the wiring harness in good condition?
1. YES: Go to Step 19.
2. NO: Repair or replace the connector. Then go to Step 1
STEP 19. Check the following items.
Check the following items, and repair or replace the defective component.
1. Check for skipped timing belt teeth.
2. Check compression.
3. EGR valve failed.
Q: Are there any abnormalities?
1. YES: Go to Step 20.
2. NO: Repair or replace the connector.
STEP 20. Replace the injector.
1. Replace the injector.
2. Carry out a test drive with the drive cycle pattern.
3. Check the diagnostic trouble code (DTC).
Q: Is the DTC P0300 set?
1. YES: Replace the ECM or PCM.
2. NO: The procedure is complete.