Multiplex Integrated Control System: Diagnosis Honda Fit GE

Troubleshooting CAN Circuit Related Problems

Note. Check the ECM/PCM for DTCs and troubleshoot ECM/PCM (see GENERAL TROUBLESHOOTING INFORMATION ) or F-CAN loss of communication errors first.

Using the B-CAN System Diagnosis Test Mode 1 (Use Only If the HDS is Unavailable)

1. Check for communication circuit problems using B-CAN System Diagnostic Test Mode 1 (see «TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE 1 AND TEST MODE 2 (WITHOUT THE HDS)»(ref-320472-S21149541942009071400000) ).
2. Check for DTCs.
3. Sort, and then troubleshoot the DTCs in this order. Battery voltage DTCs Internal error DTCs Loss of communication DTCs NOTE: If DTC B1000 is stored, troubleshoot DTC B1000 first. Signal error DTCs
4. If no DTCs are found, use B-CAN System Diagnostic Test Mode 2 to check all inputs related to the failure (see «TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE 1 AND TEST MODE 2 (WITHOUT THE HDS)»(ref-320472-S21149541942009071400000) ).

How to Clear the DTC

Set the B-CAN System Diagnosis Test Mode 1 (see TROUBLESHOOTING - B-CAN SYSTEM DIAGNOSIS TEST MODE 1 AND TEST MODE 2 (WITHOUT THE HDS) ). While in Test Mode 1, press and hold the SELECT/RESET button for more than 10 seconds.

Loss Of Communication DTC Cross-Reference Table

When an ECU is unable to communicate with the other ECUs on the B-CAN and F-CAN circuits, the other control units will set loss of communication DTCs. Use this table to find the control unit that is not communicating.

1. Find the transmitting control unit that is in the same row as all of the loss of communication DTCs retrieved.
2. Do the input test for the transmitting control unit. Bus Off and Internal Error Codes

COMMUNICATION DTC CROSS-REFERENCE TABLE

COMMUNICATION DTC CROSS-REFERENCE TABLE

DTC Troubleshooting Index

Note. Record all DTCs, all sort them by DTC type using the DTC troubleshooting index, then troubleshoot the DTC(s) in this order

1. Battery voltage DTCs
2. Internal error DTCs
3. Loss of communication DTCs (beginning with the lowest number first; for example, if B1011 and B1036 are retrieved, troubleshoot B1011 first).
4. Signal error DTCs

MICU DTC Index

MICU

MICU DTC TROUBLESHOOTING TABLE

Gauge Control Module DTC Index

Gauge Control Module

GAUGE CONTROL MODULE DTC TROUBLESHOOTING TABLE

Immobilizer-Keyless Control Unit DTC Index

Immobilizer-Keyless Control Unit

IMMOBILIZER-KEYLESS CONTROL UNIT DTC TROUBLESHOOTING TABLE

HandsFreeLink Control Unit DTC Index

HandsFreeLink Control Unit (2012 Model Without Navigation)

Note. For HandsFreeLink diagnostic trouble codes, refer to the HANDSFREELINK system article.

HANDSFREELINK CONTROL UNIT DTC TROUBLESHOOTING TABLE

Test Mode 1

Check the ECM/PCM for DTCs and troubleshoot ECM/PCM (see GENERAL TROUBLESHOOTING INFORMATION ) or F-CAN loss of communication errors first, then do this diagnosis if the HDS is not available.

Scheme 2

1. Check the No. 1 (10 A) and the No. 22 (7.5 A) fuses in the under-dash fuse/relay box. Are the fuses OK? YES - Go to step 2 . NO - Replace the fuses. If the fuse blows again, repair the short to ground on the fuse circuit(s).
2. Remove the fuse access panel (see «FUSE ACCESS PANEL REMOVAL/INSTALLATION»(ref-320473-S23909796692009071400000) ).
3. Turn the ignition switch to ON (II), and move the ceiling light switch to the middle (door) position.
4. Connect the MPCS service connector (A) to the MICU service check connector socket (B) in the under-dash fuse/relay box.
5. Wait 5 seconds, and watch the ceiling light. When the ceiling light flashes quickly once and then goes off, the system is in Test Mode 1.
6. Check for B-CAN DTCs indicated by the odo/trip LCD display on the gauge control module while still in Test Mode 1. Push the odometer select/reset button to display the next code. After you get to the last code, the display shows END. If no DTCs are stored, the display will read NO. NOTE: If the test times out, remove the MPCS service connector, turn the ignition switch to LOCK(0), and repeat step 3 and 4. Are any DTCs indicated? YES - Go to step 7 . NO - Go to step 9 .
7. Record all DTCs and sort them into these categories: Battery voltage DTCs Internal error DTCs Loss of communication DTCs Signal error DTCs
8. Clear the DTCs by pressing and holding the SELECT/RESET button for about 10 seconds.
9. You will hear a beep to confirm the codes have been cleared. Operate the devices that failed, and recheck for codes. TEST MODE 2
10. Remove the MPCS service connector from the under-dash fuse/relay box multiplex control inspection connector socket for 5-10 seconds, then re-insert it to enter Mode 2. When the system enters Mode 2, the ceiling light will flash two times quickly and then go off. NOTE: If the MPCS service connector is disconnected for too short or too long of a time, or the ignition switch is turned to LOCK (0), the system will return to Test Mode 1.
11. The following tables list the circuits that can be checked in Test Mode 2. Operate the switch that is most closely related to the problem. If the circuit is OK, the ceiling light will blink once. If the circuit is faulty, there will be no indication. MICU MICU ITEM REFERENCE TABLE Item Brake pedal position switch (ON) Driver's door switch Left rear door switch Tailgate latch switch Fog light switch Left rear door lock knob switch (UNLOCK) Wiper switch (HI/LO) Wiper switch (INT/LO) Wiper switch (MIST) Rear window wiper switch Washer switch Wiper intermittent dwell time controller Turn signal switch (LEFT) Turn signal switch (RIGHT) Hazard warning switch (ON) Headlight switch (ON) Headlight switch (OFF) Lighting switch (ON) Dimmer switch (ON) Passing switch (ON) Trunk lid opener main switch Trunk lid outer handle switch A/C pressure switch Transmission range switch (P) (A/T) Ignition key switch Hood switch Back-up light switch Wiper motor park position (Auto stop) Front passenger's door switch Right rear door switch Right rear door lock knob switch (UNLOCK) Audio unit Driver's door lock switch (UNLOCK) Driver's door lock switch (LOCK) Driver's door lock knob switch (UNLOCK) Driver's door lock knob switch (LOCK) Driver's door lock key cylinder switch (UNLOCK) (1) Driver's door lock key cylinder switch (LOCK) (1) Front passenger's door lock knob switch (UNLOCK) (1) A second key is necessary to check the key cylinder inputs. Be sure to rotate the key cylinder switch two times to each position (lock and lock, unlock and unlock) to ensure the door lock knob switch is in the appropriate position. Does the ceiling light work properly in all switch positions? YES - Go to function and input test for the system related to the failure. NO - Repair the open, short, or replace the faulty switch.

Sleep and Wake-up Mode Test

1. Shift to the sleep mode: Turn the ignition switch to LOCK (0), and remove the key, then open and close the driver's door. If the MICU receives no inputs signals, it will go into sleep mode in less than 40 seconds.
2. Confirm the sleep mode: NOTE: Check any official Honda service website for more service information about parasitic draw at the battery. Check the parasitic draw at the battery after 40 seconds; amperage should change to less than 30 mA in less than 40 seconds.
3. Shift to the wake up mode: When the ignition switch is turned to ON (II), the MICU, gauge control module, immobilizer-keyless control unit, and ECM/PCM wake up at the same time without "talking" to each other through the communication lines. When any switch in the multiplex integrated control system is turned on, it wakes up its related control unit which, in turn, wakes up the other units. After confirming the sleep mode, look in the following table for the switch most related to the problem. Operate that switch and see if its control unit wakes up. NOTE: If any control unit is faulty and will not wake up, several circuits in the system will malfunction at the same time. In the table below, is a list of the switches and the input signals that wake them up. ITEM REFERENCE TABLE Driver's door switch (door open) Left rear door switch (door open) Tailgate switch (Tailgate open) Left rear door lock knob switch Hood switch (hood open) Hazard warning switch (ON) Combination light switch (Parking, Headlight, Dimmer, Passing ON) Ignition key switch (key inserted) Driver's door key cylinder switch (LOCK/UNLOCK) Passenger's rear door lock knob (UNLOCK) Front passenger's door lock knob (UNLOCK) Driver's door lock switch (LOCK/UNLOCK) Front passenger's door switch (door open) Passenger's rear door switch (door open)

Scheme 3