Starts and shuts off, immobilizer flashing

JAKE793

MEMBER
2010 HONDA CIVIC
2.0L
4 CYL
2WD
AUTOMATIC
91,000 MILES

Hello. I had my vehicle sitting for about 4 weeks and the battery died. I tried to jump start it but when I did so the car started and then shut off 2 seconds later. There is also the green immobilizer key flashing.

I had an aftermarket remote car starter (Arctic Start) installed several months prior to this incident. The car did not even start with the remote start. At first I got a new battery and checked all the fuses to make sure they were fine, and they were. Still the same problem with the new battery.

I towed it to the place where I got the remote start and had them completely remove the remote start system, but the problem still persists.

Then, I contacted a mobile locksmith and had them diagnose it. They also checked all the fuses and scanned with their tool; after an hour they said that most likely the ECU/PCM needs to be replaced and reprogrammed. They said the key did not have to be reprogrammed because it was still programmed to the car since it still locked/unlocked the doors and showed up as having the right programming on their scantooI.

I replaced the ECU with one from another Civic and made sure that it was the correct fit/specification. Problem was still there and I checked with an odb2 and it didn't show any error codes.

Not wanting to call the locksmith back out to have them try programming and still not fixing anything I bought a set online that came with the ignition/immobilizer/key and ECU from another Civic.

Today I replaced all the components and still the vehicle has the same problem and green key is still flashing!

So lost what to do! Already spent so much money with the tows and locksmith/ECU and the set that I am really desperate at this point! Please help!

3 Replies

JACOBANDNICKOLAS

MECHANIC
109,896 POSTS

Hi,

I read through your description. At this point, I recommend having the CAN bus system scanned. CAN stands for computer/controller area network. This network is shared by all modules/computers in this vehicle. If you scan the can system, it should identify where the break down in communication is.

Here is a video that shows how this is done and why it's becoming the way of the future auto repair:

https://youtu.be/InIlnsjOVFA

A standard OBD2 scan tool may not be able to do this.

Let me know if you have questions or what is found.

Take care,
Joe

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Wednesday, July 22nd, 2020 AT 8:10 PM

JAKE793

MEMBER
2 POSTS

I ordered and used the same odb2 scanner as in the video and it does not show me any breakpoints or errors after I run the scans.

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Saturday, July 25th, 2020 AT 7:49 PM

JACOBANDNICKOLAS

MECHANIC
109,896 POSTS

That's interesting. Take a look through this set of diagnostics for the immobilizer flashing and let me know what you find. The attached two pics correlate with the directions.

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2010 Honda Civic L4-1.8L
Immobilizer Indicator Blinks
Vehicle Accessories and Optional Equipment Anti-theft and Alarm Systems Testing and Inspection Symptom Related Diagnostic Procedures Immobilizer Indicator Blinks
IMMOBILIZER INDICATOR BLINKS
Symptom Troubleshooting: Immobilizer indicator blinks

Immobilizer indicator blinks

NOTE: Before troubleshooting, check the items listed in "General Check before Troubleshooting".

1. Turn the ignition switch to LOCK (0).

2. Connect the HDS, then turn the ignition switch to ON (II).

3. Enter the IMMOBI, select the IMMOBILIZER SETUP, then select System Check, Number of keys, and Status Log.

4. Select the SYSTEM CHECK.

Is the SYSTEM CHECK indicated?
YES - Troubleshoot the immobilizer system according to the result of the SYSTEM CHECK. See: Anti-theft and Alarm Systems > Component Tests and General Diagnostics > Immobilizer System Check

NO - Go to step 5.

5. Turn the ignition switch to LOCK (0).

6. Enter the vehicle, and remove the ignition key from the ignition switch, then close the all doors.

7. Operate the key-less transmitter LOCK and UNLOCK several times in the vehicle.

Do the door lock actuators work normally?
YES - Go to step 8.

NO - Check for a poor ground (G101) and/or an open in the wire between immobilizer-key-less control unit 7P connector terminal No. 7 and body ground (G101).

8. Turn the ignition switch to ON (II).

9. Measure the voltage between immobilizer-key-less control unit 7P connector terminal No. 2 and body ground.

Is there battery voltage?
YES - Go to step 10.

NO - Repair an open in the wire between the under-dash fuse-relay box and the immobilizer-key-less control unit.

Pic 1

10. Measure the voltage between immobilizer-key-less control unit 7P connector terminal No. 7 and body ground.

Is there less than 0.2 V?
YES - Repair a poor connection or open or high resistance between immobilizer-key-less control unit 7P connector terminal No. 7 and G101.

NO - Replace the immobilizer-key-less control unit. See: Alarm Module, (Vehicle Anti-theft) > Removal and Replacement

pic 2

____________________________________

Let me know.
Joe

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