Engine Control Module (ECM) Repair Procedures

Removal

1. 1
   Disconnect the high voltage circuit. (Refer to High Voltage Disconnection Procedures)
2. 2
   Turn the ignition switch OFF and disconnect the negative (-) terminal of the auxiliary 12 V battery.
3. 3
   Remove the air cleaner assembly. (Refer to Engine Mechanical System - Intake and Exhaust System)
4. 4
   Disconnect the ECM connector (A) and remove the relay block in the engine compartment (B).

   

5. 5
   Disconnect the positive (+) terminal (A) from the battery.

   

6. 6
   Remove the reservoir mounting bolt (A) and the coolant outlet hose mounting bolt (B).

   

7. 7
   Make clearance to remove the ECM bracket mounting bolt (C) by moving the battery cable (A) and reservoir (B) as shown in the illustration below, then remove the bolt (C).

   

8. 8
   Remove the ECM (C) by loosening the nut (A) and bolt (B).

   

Installation

When replacing the ECM on a vehicle equipped with an electronic key, perform the procedure described below. [When installing a used ECM] 1 Perform the "Neutral Mode" procedure with GDS. (Refer to Body Electrical System - "Electronic Key System"). 2 Turn the ignition ON and OFF after completing the "ECM Neutral Mode". The ECM key registration process is then completed automatically. [When installing a new ECM] Turn the ignition ON and OFF after completing the "ECM Neutral Mode". The ECM key registration process is then completed automatically.

The ECM is matched with the TCM. Therefore, perform the necessary procedures after replacing or installing the ECM. (Refer to Automatic Transmission Control System - "Adjustment")

1. Install in the reverse order of removal. ECM mounting bolt: 9.8 ~ 11.8 N·m ECM bracket mounting bolt/nut: 9.8 ~ 11.8 N·m

ECM Circuit Inspection Procedure

1. 1
   ECM GROUND CIRCUIT INSPECTION: Measure the resistance between the ECM and chassis ground using the rear side of the ECM harness connector as the ECM-side checkpoint. If a problem is found, repair it.

   Specification: Below 1 Ω

2. 2
   ECM CONNECTOR INSPECTION: Disconnect the ECM connector and visually inspect the ground terminals on the ECM side and harness side for bent pins or poor contact tension. If a problem is found, repair it.
3. 3
   If the problem is not found in steps 1 and 2, the ECM may be faulty. If so, before replacing the ECM, make sure there are no DTCs with a known-good ECM, then recheck the vehicle. If DTCs were detected, check this first before replacing the ECM.
4. 4
   RECHECK ORIGINAL ECM: Install the original ECM (may be faulty) in a known-good vehicle and check the vehicle. If the problem recurs, replace the original ECM with a new one. If the problem does not occur, the problem is intermittent (refer to Intermittent Problem Check Procedure in Basic Inspection Procedure).