Mode 1 Test
Mode 1Special Tools Required
MFCS service connector 07WAZ-001010A
Description:
Mode 1 is a communication line and CPU self test. If a problem occurs on a communication wire or with an individual control unit the multiplex system will store a DTC as long as the fault is still present.
To Enter Mode 1:
1. Check the No. 9 (10 A) fuse in the driver's under-dash fuse/relay box and the No. 13 (7.5 A) fuse in the passenger's under-dash fuse/relay box.
Are the fuses OK?
YES - Go to step 2.
NO - Find and repair the cause of the blown fuse.
2. Connect the special tool to the multiplex control inspection connector (A).
3. Turn the ignition switch ON (II). If the driver's seat belt is unbuckled, the seat belt reminder will beep five times.
4. After about 5 seconds, the ignition key light should come on and the beeper should beep for 2 seconds, go off for 0.2 seconds, then blink and beep for 0.2 second. This means that you are in Mode 1 of the self-diagnosis function. Check self-diagnosis function Mode 1 for a diagnostic trouble code (DTC).
Did the multiplex system enter Mode 1?
YES - Go to step 5.
NO - Go to step 6.
5. Check for a DTC.
- If there are no DTCs present:
The ignition key light and beeper will not blink/beep again after the Mode 1 indication.
- If there is a DTC present:
About 1 second after entering Mode 1, the ignition key light and beeper indicate the DTC(s), then repeat it every 3 seconds. If there is more than one DTC, the system will indicate them in succeeding order.
Is there a DTC present?
YES - Follow the procedure in the chart above.
NO - Go to Mode 2.
6. Remove the special tool from the MFCS inspection connector.
7. Remove driver's multiplex control unit from the driver's under-dash fuse/relay box.
8. Check for voltage between the A24 terminal of the driver's under-dash fuse/relay box socket and body ground.
Is there battery voltage?
YES - Go to step 9.
NO - Replace the driver's under-dash fuse/relay box.
9. Turn the ignition switch ON (II).
10. Check for voltage between A12 terminal of the driver's under-dash fuse/relay box socket and body ground.
Is there battery voltage?
YES - Go to step 11.
NO - Repair an open in the wire between-No. 13 (7.5 A) fuse in the passenger's under-dash fuse/relay box and driver's under-dash fuse/relay box socket.
11. Check for continuity between A14 terminal of the driver's under-dash fuse/relay box socket and body ground.
Is there continuity?
YES - Go to step 12.
NO - Repair an open in the wire between driver's multiplex control unit connector and body ground. If the wire is OK, check for poor ground atG401.
12. Check for continuity between the B11 terminal of the driver's multiplex control unit connector and body ground.
Is there continuity?
YES - Go to step 13.
NO - Repair an open in the wire between the driver's multiplex control unit connector and body ground. If the wire is OK, check for poor ground atG501.
13. Check for continuity between the No. 3 terminal of the MFCS inspection connector and the A15 terminal of the driver's under-dash fuse/relay box socket.
Is there continuity?
YES - Go to step 14.
NO - Faulty driver's under-dash fuse/relay box internal circuit between the inspection connector and the driver's under-dash fuse/relay box. Replace the driver's under dash fuse/relay box.
14. Check for continuity between the No. 1 terminal of the multiplex control inspection connector and body ground.
Is there continuity?
YES - If there is still no mode 1 indication, replace the driver's multiplex control unit and recheck the symptom.
NO - Repair an open in the wire between the inspection connector and body ground. If the wire is OK, check for a poor ground at G401.