DIAGNOSTIC ITEM 16: Diagnose When The Scan Tool Cannot Receive The Data Sent By Engine Control Module (ECM): Diagnosis

WARNING: This page is about a different car, the 2017 Mitsubishi Mirage. However, it is still accessible from the selected car via links, so may be relevant.

STEP 1. Connector check: joint connector (CAN2) and engine control module (ECM) connector
CAUTION: The strand end of the twist wire should be within 10 cm (4 inches) from the connector. For details refer to SERVICE PRECAUTIONS .

When checking the joint connector, ensure that its wiring harness side and its short pins are not damaged.

Q: Is the check result normal?
1. YES: Go to Step 2.
2. NO: Repair the faulty connector. Replace the joint connector as necessary.
STEP 2. Resistance measurement at joint connector (CAN2) and engine control module (ECM) connector.
CAUTION:
- A digital multimeter should be used. For details refer to SERVICE PRECAUTIONS .
- The test wiring harness should be used. For details refer to SERVICE PRECAUTIONS .
- Strictly observe the specified wiring harness repair procedure. For details refer to SERVICE PRECAUTIONS .
1. Disconnect the joint connector (CAN2) and the engine control module (ECM) connector, and measure at the wiring harness side.
2. Turn the ignition switch to the "LOCK" (OFF) position.
  CAUTION: When measuring the resistance, disconnect the negative battery terminal. For details refer to SERVICE PRECAUTIONS .
3. Ensure that the negative battery terminal is disconnected.
4. Continuity between joint connector (CAN2) terminal No. 11 and engine control module (ECM) connector terminal No. 101
  OK: Continuity (2 Ω or less)
5. Continuity between joint connector (CAN2) terminal No. 22 and engine control module (ECM) connector terminal No. 102
  OK: Continuity (2 Ω or less)
Q: Is the check result normal?
1. YES: <All the resistances measure 2 Ω or less> Go to Step 3.
2. NO: <Either or all of the resistances measure more than 2 > Repair the wiring harness between joint connector (CAN2) and the engine control module (ECM).
STEP 3. Resistance measurement at engine control module (ECM) connector.
CAUTION: A digital multimeter should be used. For details refer to SERVICE PRECAUTIONS .
1. Remove the engine control module (ECM), and measure at the equipment side.
2. Resistance between engine control module (ECM) connector terminal Nos. 101 and 102
  OK: 120 ± 20 Ω
Q: Is the check result normal?
1. YES: <Within 120 ± 20 > Power supply to the engine control module (ECM) may be suspected. Diagnose the fuel system. Refer to TROUBLESHOOTING .
2. NO: <Not within 120 ± 20 > Replace the engine control module (ECM).