Anti theft alarm preventing car from starting?

Hello,

I would disconnect the battery for 5 minutes and then turn the key on, then reconnect the battery here is a guide that will tell you more on how to reset the security system.

https://www.2carpros.com/articles/how-to-reset-a-security-system

Please run down this guide and report back.

Just so I understand, the engine starts, the alarm is going off but it won't go in gear? If the engine starts, that will make this very odd.

However, if the engine does not start then we have an active theft system and this is causing the not going into gear issue.

Here is a guide on security systems. If disarming the system that is spelled out here does not work, you can try to leave the key in the ignition for 30 minutes in the on position and see if the alarm will deactivate.

https://www.2carpros.com/articles/how-to-reset-a-security-system

Maybe getting a video of what it is doing will get us on the same page if I am not stating this correctly. Thanks

P0603 DTC code which refers to the Keep Alive Memory in the PCM power-train control module. This is telling us the PCM needs to be replaced or the internal battery replaced. (I am not sure if you can replace the battery.) This should take care of the security issue as well. Here is the PCM location and how to replace it. Please give your VIN number to the re-builder when purchasing the unit.

HDS Clear Command

The ECM/PCM stores various specific data to correct the system even if there is no electrical power such as when the battery negative terminal or No. 8 FI ECU (ECM/PCM) (15 A) fuse are disconnected. Stored data based on failed parts should be cleared by using the "CLEAR COMMAND" of the HDS, if parts are replaced.

The HDS has three kinds of clear command to meet the purpose. They are DTC clear, ECM/PCM clear, and CKP pattern clear. DTC clear command erases all stored DTC codes, freeze data, and readiness codes. This must be done with the HDS after reproducing the DTC during troubleshooting. The ECM/PCM clear command erases all stored DTC codes, freeze data, readiness codes, and all specific data to correct the system except CKP pattern. If the CKP pattern data in the ECM/PCM was cleared, you must do the CKP pattern learn procedure. The CKP pattern clear command erases only CKP pattern data. This command is for repair of a misfire or the CKP sensor.

DTC CLEAR

1. Clear the DTC with the HDS while the engine is stopped.
2. Turn the ignition switch OFF.
3. Turn the ignition switch ON (II). Wait for 30 seconds.
4. Turn the ignition switch OFF, and disconnect the HDS from the DLC.

ECM/PCM RESET

This command clears stored specific data from each vehicle such as DTCs, freeze data, and readiness codes. It does not clear CKP PATTERN data.

1. Reset the ECM/PCM with the HDS while the engine is stopped.
2. Turn the ignition switch OFF.
3. Turn the ignition switch ON (II). Wait for 30 seconds.
4. Turn the ignition switch OFF, and disconnect the HDS from the DLC.
5. Do the ECM/PCM idle learn procedure.

CKP PATTERN CLEAR/CKP Pattern Learn Procedure

Enable Criteria

ECT at 176 °F (80 °C) or higher.

Procedure

1. Clear the CKP pattern with the HDS while the engine is stopped.
2. Turn the ignition OFF.
3. Turn the ignition ON (II), and wait for 30 seconds.
4. Test-drive the vehicle on a level road. Decelerate (with the throttle fully closed) from an engine speed of 2,500 rpm to 1,000 rpm with the A/T in 2, or the M/T in 2nd or 3rd gear.
5. Stop the vehicle. Do not turn the ignition off.
6. Select the ALL DATA LIST in the DATA LIST MENU of the HDS.
7. Check the status of PULSER F/B LEARN. If it is set to NG, the enable criteria was probably not met; repeat the procedure from the beginning.

How to End a Troubleshooting Session (required after any troubleshooting)

1. Reset the ECM/PCM with the HDS.
2. Do the ECM/PCM idle learn procedure.
3. Turn the ignition switch OFF.
4. Disconnect the HDS from the DLC.

NOTE: The ECM/PCM Is part of the immobilizer system. If you replace the ECM/PCM, it will have a different immobilizer code. In order for the engine to start, you must rewrite the immobilizer code with the HDS.

Check out the diagrams (below). Please let us know what happens.

Hi,

You will need to register the new key with the immobilizer on your vehicle. It requires a Honda diagnostic scan tool or equal. If this isn't done, the vehicle will not recognize the new key and the engine won't run. It can be done without the old key, but.

Here are the directions:

2004 Honda Accord L4-2.4L
Immobilizer Key Registration
Vehicle Accessories and Optional Equipment Antitheft and Alarm Systems Testing and Inspection Programming and Relearning Immobilizer Key Registration
IMMOBILIZER KEY REGISTRATION
Immobilizer Key Registration

NOTE:
- The HDS is required for registration of the immobilizer keys.
- Check for aftermarket electrical equipment that can cause problems with transponder operation.
- The immobilizer control unit-receiver can store up to six immobilizer Keys.

Add a new key

1. Have a registered key, a new immobilizer key, and the first pass word from the IN system.
2. Connect the HDS to the data link connector.
3. Turn the ignition switch ON (II).
4. Select "IMMOBILIZER" from the "SYSTEM SELECT" menu.
5. Select "Keys", then "Add 1 key".
6. Do the registration according to the instruction of HDS screen.
7. Check if the engine can be started by the newly registered key.

Add new keys

1. Have a registered key, all new keys, and the immobilizer PCM code.
2. Connect the HDS to the data link connector.
3. Turn the ignition switch ON (II).
4. Select "IMMOBILIZER" from the "SYSTEM SELECT" menu.
5. Select "Add and Delete Keys", or "Delete or Add Multiple Keys".
6. Do the registration according to the instruction of HDS screen.
7. Check if the engine can be started by all the registered keys.

Replace any of the keys

NOTE: If any of the registered keys were lost, do the following procedure to delete the lost registered key.

1. Have at least one original key, all other keys to be registered and the immobilizer PCM code.
2. Connect the HDS to the data link connector.
3. Turn the ignition switch ON (II).
4. Select "IMMOBILIZER" from the "SYSTEM SELECT".
5. Select "KEYS", then "REWRITE KEYS".
6. Do the registration according to the instruction of HDS screen.
7. Check if the engine can be started by all the registered keys.

All keys are lost

1. Prepare all new keys and have the immobilizer PCM code.
2. Connect the HDS to the data link connector.
3. Turn the ignition switch ON (II).
4. Select "IMMOBILIZER" from the "SYSTEM SELECT" menu.
5. Select "KEYS", then "ALL KEYS LOST".
6. Do the registration according to the instruction of HDS screen.
7. Check if the engine can be started by all the registered keys.

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I have a feeling this isn't what you wanted to hear. If you have other questions, let me know.

Take care,
Joe

No problem. Is that what you needed?

Joe

Yes, the security system is engaged. lets try to reset the system. please use this guide and get back to me:

https://www.2carpros.com/articles/how-to-reset-a-security-system

Please run down this guide and report back.

Hello,
It sounds like the door lock is the issue it must work so the security system can be disarmed. Here is a wring diagram of the alarm system so you can see how it works. Can I ask what happens tot he door lock and what do you need to fix it? It sounds like one of the horns is shorted causing the fuse to blow. You can see by the wiring diagrams the door locks and latches must be working. Also, check the system fuses. The wiring diagrams will show you which ones.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Check out the diagrams (below). Please run this test and get back to us.

Cheers, Ken

Hi RAY,

The triggering points for the alarm are the door and hood switches. Most often an out of alignment door would cause the door switch to come into contact triggering the alarm.

This guide can help us

https://www.2carpros.com/articles/how-to-reset-a-security-system

If you have in instances witnessed the door ajar indicator flashing while driving, the at least one of the door switch is not fully in contact. Check the door switches for missing rubber seals, stoppers.

The other item to check would be the hood switch, ensure it is correctly adjusted.

Hi Kkhondaaccord,

Do you mean the alarm is an aftermarket system?

Aftermarket alarm system comes in many varieties and each have different reset methods. Most would be equipped with a reset button. Check underdash for a small push button type switch and turn ignition switch to ON then press the switch to reset.

If that fails, remove the alarm fuse, turn ignition switch on and plug in the alarm fuse.

After resetting the alarm if the remotes do not work, reprogramming would be required.