DTC B1702: Reception error of encrypted code: Diagnosis

Required Special Tools:

MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A

STEP 1. Check for presence of other key or things that interferes communication (such as magnets and equipment that generates radio waves) near the key in the ignition.
Q: Is there any other key near the key in the ignition?
1. YES: Move the other key or things that interferes communication (such as magnets and equipment that generates radio waves) well away from key being used. Retest the system.
2. NO: Go to Step 2.
STEP 2. Check that the engine start using the spare ignition key which encrypted code has been registered.
Q: Does the engine start using the spare ignition key for which the encrypted code has been registered?
1. YES: Replace the ignition key and then register the ID codes again (Refer to IGNITION KEY REMINDER TONE ALARM AND DOOR LOCK PREVENTION FUNCTION DIAGNOSIS .). Retest the system.
2. NO: Go to Step 3.
STEP 3. Recheck for diagnostic trouble code.
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. Use scan tool MB991958 to check immobilizer system diagnostic trouble codes.
4. Turn the ignition switch to "LOCK" (OFF) position.
5. Disconnect scan tool MB991958.
  Q: Which DTC is set, DTC B1702 or B1703?
  
  DTC B1703 is set: Refer to DTC B1703: ENCRYPTED CODE INCONSISTENT .
  
  DTC B1702 is set: Go to Step 4.
  
  Fig 1: Connecting Special Tool To Data Link Connector
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 4. Check the key reminder switch (ignition key ring antenna).
1. Disconnect the key reminder switch (ignition key ring antenna) connector C-310.
  
  Fig 2: Key Reminder Switch Connector C-310
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. Measure the resistance value between terminal number 3 and terminal number 7.
  - The measured value should be 7.65 - 9.35 ohm.
  Q: Is the check result normal?
  1. YES: Go to Step 5.
  2. NO: Replace the key reminder switch (ignition key ring antenna). Retest the system.
    
    Fig 3: Measuring Resistance Value Between Terminal Number 3 And Terminal Number 7
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 5. Check ETACS-ECU connector C-218 and key reminder switch (ignition key ring antenna) connector C-310 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Are ETACS-ECU connector C-218 and key reminder switch (ignition key ring antenna) connector C-310 in good condition?
1. YES: Go to Step 6.
2. NO: Repair or replace the damage component(s). Confirm that scan tool MB991958 communicates normally.
  
  Fig 4: ETACS-ECU Connector C-218
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  
  Fig 5: Key Reminder Switch Connector C-310
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 6. Check the wiring harness between ETACS-ECU connector C-218 (terminals 57 and 58) and key reminder switch (ignition key ring antenna) connector C-310 (terminals 3 and 7).
- Check the signal line for open circuit and short circuit.
  Q: Are the wiring harness between ETACS-ECU connector C-218 (terminal 57 and 58) and key reminder switch (ignition key ring antenna) connector C-310 (terminal 3 and 7) in good condition?
  1. YES: Replace the ETACS-ECU and register the ID codes again (Refer to ENCRYPTED CODE REGISTRATION CRITERIA TABLE .). Retest the system.
  2. NO: Repair or replace the damaged component(s). Confirm that scan tool MB991958 communicates normally.
    
    Fig 6: ETACS-ECU Connector C-218
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
    
    Fig 7: Key Reminder Switch Connector C-310
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.