2. Switch on the ignition by turning the key to position «ON» (II).
3. Verify that the HDS is communicating with the vehicle and the ECM. If not, troubleshoot the DLC circuit.
4. Check if DTCs appear on the screen. If a DTC is present (DTC), diagnose and correct the cause of the problem before proceeding with the test.
5. Turn the ignition key to position «OFF». Disconnect the 4P connector from the alternator.
6. Start the engine and turn on the high beam headlights.
7. Measure voltage between alternator connector terminal #2 4P and battery positive.
Is there a voltage of 1 V or less here?
- YES - go to step 11.
- NO - go to step 8.
8. Connect the SCS Service Check Signal circuit to the HDS diagnostic system, then turn the ignition key to «OFF».
Note. This action is necessary to prevent failure of the engine control unit (ECM).
9. Disconnect the 44P connector B of the ECM.
10. Check for continuity in wire between ECM connector terminal B41 and «weight» body.
Is the connection continuous?
- YES - Repair short in the wire between the alternator and the ECM.I
- NO - Update the ECM if it does not have the latest software, or temporarily substitute a known-good ECM, then recheck. If the problem persists with a known-good ECM, replace the removed ECM.
11. Connect the SCS service test signal circuit to the HDS diagnostic system, then turn the ignition key to «OFF».
Note. This action is necessary to prevent failure of the engine control unit (ECM).
12. Disconnect the 44P connector B of the ECM.
13. Check for continuity between ECM connector terminal B41 and alternator connector terminal No. 2 4P.
Is the connection continuous?
- YES - Replace the alternator or repair it.
- NO - Repair open in the wire between the alternator and the ECM.