MICU Input Test
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2020 Honda Fit, 2019 Honda Fit, 2018 Honda Fit, 2017 Honda Fit, and 2016 Honda Fit. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
- If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A - Refer to: or Body Electrical Troubleshooting - B-CAN System Diagnosis Test Mode A - Initial Communication and DTC Checks .
- Before testing, check for DTCs. If any DTCs are indicated, troubleshoot those DTCs first.
- Before testing, make sure the No. B21 (15 A) and No. B29 (10 A) fuses in the under-hood fuse/relay box is OK.
1. Turn the vehicle to the OFF (LOCK) mode
2. Disconnect under-dash fuse/relay box connectors D, G, H, N, and Q.
NOTE: All connector views are shown from the wire side of the female terminals.
3. Inspect the connectors and socket terminals to be sure they are all making good contact:
- If the terminals are bent, loose, or corroded, repair them as necessary, and recheck the system.
- If the terminals are OK, go to step 4 below.
4. With the connectors still disconnected, do the following input tests:
- If any test indicates a problem, find and correct the cause, then recheck the system.
- If all the input tests prove OK, go to step 5 below.
| Cavity | Wire | Test condition | Test: Desired result | Possible cause if desired result is not obtained |
|---|---|---|---|---|
| G2 | PNK | Disconnect the gauge control module 32P connector | Check for continuity between terminal G2 and gauge control module 32P connector terminal No. 23: There should be continuity. | An open in the B-CAN wire |
| G3 | BLU | Check for continuity between terminal G3 and gauge control module 32P connector terminal No. 24: There should be continuity. | ||
| G2 | PNK | Disconnect the climate control unit 32P connector | Check for continuity between terminal G2 and climate control unit 32P connector terminal No. 6: There should be continuity. | An open in the B-CAN wire |
| G3 | BLU | Check for continuity between terminal G3 and climate control unit 32P connector terminal No. 7: There should be continuity. | ||
| G2 | PNK | Disconnect the automatic lighting control unit/sensor 7P connector | Check for continuity between terminal G2 and automatic lighting control unit/sensor 7P connector terminal No. 6: There should be continuity. | An open in the B-CAN wire |
| G3 | BLU | Check for continuity between terminal G3 and automatic lighting control unit/sensor 7P connector terminal No. 7: There should be continuity. | ||
| G2*1 | PNK | Disconnect the immobilizer-keyless control unit 7P connector | Check for continuity between terminal G2 and immobilizer-keyless control unit 7P connector terminal No. 4: There should be continuity. | An open in the B-CAN wire |
| G3*1 | BLU | Check for continuity between terminal G3 and immobilizer-keyless control unit 7P connector terminal No. 5: There should be continuity. | ||
| G2*2 | PNK | Disconnect keyless access control unit connector C (20P) | Check for continuity between terminal G2 and keyless access control unit connector C (20P) terminal No. 1: There should be continuity. | An open in the B-CAN wire |
| G3*2 | BLU | Check for continuity between terminal G3 and keyless access control unit connector C (20P) terminal No. 11: There should be continuity. | ||
| G2*3 | PNK | Disconnect audio unit connector B (20P) | Check for continuity between terminal G2 and audio unit connector B (20P) terminal No. 13: There should be continuity. | An open in the B-CAN wire |
| G3*3 | BLU | Check for continuity between terminal G3 and audio unit connector B (20P) terminal No. 3: There should be continuity. | ||
| G2*4 | PNK | Disconnect audio unit connector C (24P) | Check for continuity between terminal G2 and audio unit connector C (24P) terminal No. 24: There should be continuity. | An open in the B-CAN wire |
| G3*4 | BLU | Check for continuity between terminal G3 and audio unit connector C (24P) terminal No. 12: There should be continuity. | ||
| G2*5 | PNK | Disconnect audio-navigation unit connector B (20P) | Check for continuity between terminal G2 and audio-navigation unit connector B (20P) terminal No. 13: There should be continuity. | An open in the B-CAN wire |
| G3*5 | BLU | Check for continuity between terminal G3 and audio-navigation unit connector B (20P) terminal No. 3: There should be continuity. | ||
| D13 | LT BLU | Under all conditions | Check for continuity between terminal D13 and data link connector (DLC) terminal No. 7: There should be continuity. | An open in the K LINE wire |
*1: Without keyless access system
*2: With keyless access system
*3: With display audio
*4: With color audio
*5: With navigation
5. Reconnect the connectors to the under-dash fuse/relay box, and do the following input tests:
- If any test indicates a problem, find and correct the cause, then recheck the system.
- If all the input tests prove OK, the MICU must be faulty; replace the under-dash fuse/relay box .
| Cavity | Wire | Test condition | Test: Desired result | Possible cause if desired result is not obtained |
|---|---|---|---|---|
| Q15 | RED | Under all conditions | Measure the voltage to ground: There should be battery voltage. |
|
| D23 | BLK | In all power modes | Measure the voltage to ground: There should be less than 0.2 V. |
|
| H1 | BLK | In all power modes | Measure the voltage to ground: There should be less than 0.2 V. |
|
| N6 | BLK | In all power modes | Measure the voltage to ground: There should be less than 0.2 V. |
|
| N38 | BLK | In all power modes | Measure the voltage to ground: There should be less than 0.2 V. |
|