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Inspection Procedure A-3: The power liftgate automatic operation does not work normally (both the open operation and close operation do not work).
 
 
cautionBefore replacing the ECU, ensure that the input and output signal circuits are normal.
 
 
 
 
COMMENTS ON TROUBLE SYMPTOM
Component other than Mitsubishi genuine parts or accessories is fitted on the liftgate. The quarter trim interferes with the power liftgate motor arm. There may also be a malfunction in one of the followings; the liftgate gas spring, the door-ajar switch system, the power liftgate main switch system, the liftgate sensor system, the wiring harness or its connector(s) between the battery and the power liftgate control unit, the wiring harness or its connector(s) between the power liftgate control unit and body ground, the power liftgate motor itself or the power liftgate control unit itself.
 
 
PROBABLE CAUSES
  • A component other than Mitsubishi genuine parts or accessories is fitted on the liftgate.
  • The quarter trim interferes with the power liftgate motor arm.
  • Door-ajar switch system failed
  • Power liftgate main switch system malfunction
  • Liftgate sensor system malfunction
  • Damaged liftgate gas spring
  • Damaged power liftgate motor
  • Damaged power liftgate control unit
  • Damaged wiring harness and connectors
 
 
DIAGNOSIS
Required Special Tools:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. Parts installation check of liftgate
Check whether a component other than Mitsubishi genuine parts or accessories is fitted on the liftgate.
Is the check result normal?
Go to Step 2.
Remove the components other than Mitsubishi genuine parts or accessories.
 
STEP 2. Liftgate gas spring check
Visually check the liftgate gas spring for damage. Also, check the manual operation for any problems such as the operation is too light or too heavy.
Is the check result normal?
Go to Step 3.
Replace the liftgate gas spring.
 
STEP 3. Interference inspection: quarter trim and power liftgate motor arm
Check whether the quarter trim interferes with the power liftgate motor arm.
Is the check result normal?
Go to Step 4.
Install the power liftgate control unit or the quarter trim securely.
 
STEP 4. Using scan tool (M.U.T.-IIISE), check data list.
Check the signals related to the power liftgate operation.
  • power liftgate main switch: OFF → ON
  • Door-ajar switch: OFF → ON
  • Liftgate sensor LH: OFF → ON
  • Liftgate sensor RH: OFF → ON
 
Item No.Item nameNormal conditions
1Main switchOFF → ON
7Half door switchOFF → ON
9Touch sensor (Left)OFF → ON
10Touch sensor (Right)OFF → ON
12ECU power supply voltageSystem voltage
OK: Normal conditions are displayed for all the items.
Is the check result normal?
: Go to Step 5.
: Refer to Inspection Procedure B-1 "power liftgate main switch signal is not received" .
: Refer to Inspection Procedure B-4 "Door-ajar switch signal is not received" .
: Refer to Inspection Procedure B-7 "liftgate sensor signal is not received" .
: Refer to Inspection Procedure A-1 "Power supply voltage abnormality of power liftgate control unit" .
 
STEP 5. Check of the troubles
Check whether the power liftgate works normally.
Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction .)
Replace the power liftgate control unit.