Test 12 - Vacuum Switching Valve (Code 25 And 53)
- Check vacuum switching valve. See FUEL INJECTION SYSTEM - ISUZU I-TEC EFI article in Fuel Injection section. Unplug ECU connectors at ECU, and at vacuum switching valve. If trouble code 25 is present, go to step 2). If trouble code 53 is present go to step 4).
- Turn ignition on. Connect a voltmeter between vacuum switching valve Black/White feed wire and ground. Voltage reading should be 12 volts. Turn ignition switch off. If reading is incorrect, repair or replace harness.
- Connect an ohmmeter between vacuum switching valve Lt. Green/Yellow feed wire and ECU connector terminal No. 35. Ohmmeter resistance should be 0 ohms. If resistance is incorrect, repair or replace harness.
- Connect an ohmmeter between ECU connector terminal No. 23 and ground. Ohmmeter resistance should be 0 ohms. If resistance is incorrect, repair or replace harness.