DIAGNOSTIC ITEM 10: Diagnose when the scan tool cannot receive the data sent by ECM: Diagnosis

WARNING: This page is about a different car, the 2008 Mitsubishi Lancer. However, it is still accessible from the selected car via links, so may be relevant.

Required Special Tools:

MB991223: Harness Set
MB992006: Extra Fine Probe
MB992110: Power plant ECU check harness

STEP 1. Check joint connector (CAN3) C-127 < M/T >, joint connector (CAN4) A-14 < TC-SST >, ECM connector B-10 and intermediate connector A-13 < TC-SST > for loose, corroded or damaged terminals, or terminals pushed back in the connector.
CAUTION: The strand end of the twisted wire should be within 10 cm (4 inches) from the connector. For details refer to SERVICE PRECAUTIONS .

Q: Are joint connector (CAN3) C-127 < M/T >, joint connector (CAN4) A-14 < M/T >, ECM connector B-10 and intermediate connector A-13 < TC-SST > in good condition?

YES : Go to Step 2.

NO : Repair the damaged parts.
STEP 2. Check the wiring harness between joint connector (CAN3) C-127 < M/T > or joint connector (CAN4) A-14 < TC-SST > and ECM connector B-10.
CAUTION: Strictly observe the specified wiring harness repair procedure. For details refer to SERVICE PRECAUTIONS .
1. Disconnect joint connector (CAN3) C-127 and ECM connector B-10, and check the wiring harness.
2. Check the wiring harness between joint connector (CAN3) C-127 (terminal 4) and ECM connector B-10 (terminal 90) < M/T >
  OK: Continuity exists (2 Ω or less)
  
  Fig 1: Checking Wiring Harness Between Joint Connector (CAN3) And ECM Connector Terminals (M/T)
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
3. Check the wiring harness between joint connector (CAN3) C-127 (terminal 15) and ECM connector B-10 (terminal 91) < M/T >
  OK: Continuity exists (2 Ω or less)
  
  Fig 2: Checking Wiring Harness Between Joint Connector (CAN3) And ECM Connector Terminals (M/T)
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
4. Check the wiring harness between joint connector (CAN4) A-14 (terminal 7) and ECM connector B-10 (terminal 90) < TC-SST >
  OK: Continuity exists (2 Ω or less)
  
  Fig 3: Checking Wiring Harness Between Joint Connector (CAN4) And ECM Connector Terminals (TC-SST)
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
5. Check the wiring harness between joint connector (CAN4) A-14 (terminal 20) and ECM connector B-10 (terminal 91) < TC-SST >
  
  Fig 4: Checking Wiring Harness Between Joint Connector (CAN4) And ECM Connector Terminals (TC-SST)
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  
  OK: Continuity exists (2 Ω or less)
Q: Is the wiring harness between joint connector (CAN3) C-127 < M/T > or joint connector (CAN4) A-14 < TC-SST > and ECM connector B-10 in good condition?

YES : Check the power supply circuit of the ECM. Refer to MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS .

NO : Repair the wiring harness between joint connector (CAN3) C-127 < M/T > or joint connector (CAN4) A-14 < TC-SST > and ECM connector B-10.