How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Pete Your Own Question
Pete
Pete, Auto Service Technician
Category: Honda
Satisfied Customers: 24659
Experience:  Over 17 years diagnosing and repairing automobiles various makes and models with some training and certifications.
14928985
Type Your Honda Question Here...
Pete is online now
A new question is answered every 9 seconds

I have a 2009 Civic. I was driving home last night when the

Customer Question

I have a 2009 Civic. I was driving home last night when the DRL came on the dash and I no longer had bright lights. I have cheched the fuses and all are good.
Submitted: 10 months ago.
Category: Honda
Expert:  Pete replied 10 months ago.

Hi my name is ***** ***** I will be happy to assist with this today.In some cases I may need more info to assist better.I apologize for any delay.

What usually fails here and causes this issue is a fault with the MICU itself located in the under dash fuse panel.This MICU control unit receives the signals from the dimmer switch from low to high beam and then sends the signals to the head lights.This also controls the DRL light itself.The MICU fails internally needing replaced to correct this fault here.The MICU is replaced as a complete assembly with the under dash fuse panel.This will require one programmed key,and the PCM code from a dealer.In most all cases it has to be replaced by a dealer in order for it to be keyed and coded properly for proper operation.

The signals in and out of the MICU will need to be tested to verify that this is the cause here for sure before having it replaced.

If more help is needed, use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service.You can rate at any time and we can continue to work on your question as this will not close out your question.Keep in mind in some cases it can be difficult to fully diagnose or help repair your vehicle without seeing it and I work on delivering the best possible answer from what I see to work with.

Thanks Pete

Customer: replied 10 months ago.
how do I test the unit before I take it to the dealer?i
Expert:  Pete replied 10 months ago.

There is a test procedure to make sure this is the cause here.I will post it below.You will need a multi meter and a test light to test this here.The MICU is part of the under dash fuse panel so you will need to access the wiring and connections to it.Here is the testing procedure for this here.

Exterior Lights MICU Input Test

NOTE: - The MICU turns on the headlights (high beams) in a dimming mode for the Daytime Running Lights under the following conditions: - With the ignition switch turned to ON (II). - The headlight switch OFF. - The parking brake is released (parking brake switch OFF). - The DRL indicator will come on when one of the headlight (high beams) bulbs is blown, or if the high beam wiring has an open circuit with the daytime running lights ON. - For Canada models: If the vehicle is equipped with an optional remote control engine start system, the daytime running lights will not function when started with the remote start.

1. Before testing the lighting system, troubleshoot the system using B-CAN System Diagnosis Test Mode A.(you can skip this test)

2. Check the No. 12 (10 A), No. 13 (10 A), No. 15 (7.5 A), No. 16 (10 A), No. 17 (10 A), No. 18 (20 A), No. 19 (15 A), and No. 21 (20 A), and No. 37 (7.5 A) fuses in the under-dash fuse/relay box. If any fuse is blown, replace it and go to step 3.

3. Disconnect under-dash fuse/relay box connectors E, F, G, S, and T. NOTE: All connector views are shown from wire side of female terminals.

4. Inspect the connector 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 look OK, go to step 5.

5. With the connector still disconnected, do these input tests at the following connectors. - 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 6.

https://www.dropbox.com/s/ndtf2d5u6e200dv/t-01-24.gif?dl=0

6. Reconnect the connectors to the under-dash fuse/relay box, and do these input tests at the following connectors. - 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.

https://www.dropbox.com/s/jy183jua1q8ajf0/te-01-24.gif?dl=0

https://www.dropbox.com/s/bee3b1m2zyh38oy/tes-01-24.gif?dl=0

https://www.dropbox.com/s/jeo79vlkqxvtp8q/test-01-24.gif?dl=0

If you do not have the tools to test this here this will need done by someone that does have the correct test equipment.

Let me know if you need anything else and feel free to rate my help here.

Thanks Pete

Customer: replied 10 months ago.
I changed the light bulbs. No more problems.
Expert:  Pete replied 10 months ago.

That is great to hear.If you need anything else let me know and feel free to rate my help here as this is how I receive credit for my time.

Thanks Pete