Replacing the ECM/PCM
REPLACING THE ECM/PCMIf you replace the ECM/PCM, you must program (rewrite) it with the HDS to accept the transponder codes sent from the immobilizer receiver, or the engine will not start. Use the appropriate procedure below to rewrite the ECM/PCM.
Replacing the ECM/PCM in 1998-99 Accord and 1998 Odyssey
Preparation
To replace the ECM/PCM, you need these items:
^ Replacement ECM/PCM
^ All of your customer's programmed ignition keys (master and valet) for the vehicle. (This includes any master or valet keys with a T5 stamped on the shank or molded into the grip. These are duplicate keys made with the Ilco Immobilizer Key Code Duplicator.)
^ HDS with the latest software
NOTE:
Make sure the setup and time are correct before you use the HDS. Select the F12 key in the upper right corner to get the Set-up Details screen. Make sure Market: is set to USA. Select the time display in the lower right corner to get the Date/Time Properties pop-up window. Make sure the date and time are correct. For details, refer to the Honda Diagnostic System (HDS) Setup Instructions listed under Tool Information in ISIS.
^ PCM code
NOTE:
If you cannot log in to the iN screen on the HDS, you must retrieve the PCM code from the Immobilizer Code Inquiry in the iN.
Procedure
1. Replace the ECM/PCM. Refer to the Fuel and Emissions section of the appropriate service manual, and follow the procedure.
2. Gather all of your customer's programmed ignition keys (master and valet) for the vehicle. Set aside any T5 keys.
3. Stick a small piece of masking tape to the grip of each programmed ignition key. Mark them as A, B, C, etc. (The ECM/PCM stores a maximum of six transponder codes.)
4. Connect the HDS to the 16P data link connector (DLC).
5. Insert key A into the ignition switch, and turn the switch to ON (II). Turn on the HDS, then log in to the iN screen.
6. At the screen prompts, enter the VIN and the odometer reading, then verify the correct date and time.
7. From the System Selection Menu screen, select IMMOBI.
8. From the Mode Menu screen, select Immobilizer Setup.
9. From the Immobilizer Test Mode Menu screen, select Replace ECMIPCM.
10. Follow the on-screen prompts. If your HDS is not logged in to the iN, you will have to enter the PCM code you have retrieved from the iN Immobilizer Code Inquiry to proceed. When you are finished, turn the ignition switch to LOCK (0), then turn off and disconnect the HDS.
11. T5 keys only: Start the engine with each of the T5 keys you set aside in step 2.
^ If all of the T5 keys start the engine, the transponder codes are already recognized by the ECMIPCM and the immobilizer procedure is complete.
^ If any of the T5 keys do not start the engine, go to step 12.
12. The HDS accepts only one key of a certain transponder code. If the total number of nonprogrammed T5 keys plus the keys you entered is greater than six, use the key code duplicator to recode the additional T5 keys to match an existing transponder code.
NOTE:
The HDS shows you the number of transponder codes stored in the memory of the ECM/PCM. If any of the keys share the same transponder code (as might be the case with a T5 key), the number of codes shown may be fewer than the actual number of keys.
13. Do the idle learn procedure:
^ Make sure all electrical items (A/C, audio unit, defogger, lights, etc.) are turned off, then start the engine.
^ Let the engine reach its normal operating temperature (the cooling fans cycle twice).
^ Let the engine idle (throttle fully closed and with all electrical items off) for 10 minutes.
Replacing the ECM/PCM in 2000-02 Accord, 1999-04 Odyssey, 2003-04 Pilot, 2000-05 S2000, and 2000-06 Insight
NOTE: These models have an enhanced immobilizer system. You can rewrite the new ECM/PCM with the HDS using just one programmed ignition key. Make sure you download the transponder codes from the original ECM/PCM to the HDS before replacing it.
Preparation
To replace the ECM/PCM, you need these items:
^ One programmed ignition key (master, valet, T5) for the vehicle
^ HDS with the latest software
NOTE:
Make sure the setup and time are correct before you use the HDS. Select the F12 key in the upper right corner to get the Set-up Details screen. Make sure Market: is set to USA. Select the time display in the lower right corner to get the Date/Time Properties pop-up window. Make sure the date and time are correct. For details, refer to the Honda Diagnostic System (HDS) Setup Instructions listed under Tool Information in ISIS.
^ PCM code
NOTE:
If you cannot log in to the iN screen on the HDS, you must retrieve the PCM code from the Immobilizer Code Inquiry in the iN.
Procedure
Downloading From the Original ECM/PCM
1. Connect the HDS to the 16P data link connector (DLC).
2. Insert the programmed key into the ignition switch, and turn the ignition switch to ON (II). Turn on the HDS, then log in to the iN screen.
3. At the screen prompts, enter the VIN and the odometer reading, then verify the correct date and time.
4. From the System Selection Menu screen, select IMMOBI.
5. From the Mode Menu screen, select Immobilizer Setup.
6. From the Immobilizer Test Mode Menu screen, select Replace ECM/PCM using 1 original key.
7. From the Replace ECM/PCM using 1 original key screen, select Begin to Replace ECM/PCM Using 1 Original Key.
8. Follow the on-screen prompts. If your HDS is not logged in to the iN, you will have to enter the PCM code you have retrieved from the iN Immobilizer Code Inquiry to proceed. (During the procedure, all immobilizer key transponder codes are automatically downloaded from the original ECM/PCM to the HDS. During the download process, make sure the ignition switch remains turned to ON (II), and the HDS stays connected.)
9. When the downloading is complete, turn the ignition switch to LOCK (0).
10. Replace the ECM/PCM. Refer to the Fuel and Emissions section of the appropriate service manual.
Uploading to the New ECM/PCM
11. Turn the ignition switch to ON (II). Keep following the screen prompts on the HDS. (All the transponder codes are automatically uploaded to the new ECM/PCM.)
12. When the uploading is complete, turn the ignition switch to LOCK (0), then turn off and disconnect the HDS.
13. Do the idle learn procedure:
^ Make sure all electrical items (A/C, audio unit, defogger, lights, etc.) are turned off, then start the engine.
^ Let the engine reach its normal operating temperature (the cooling fans cycle twice).
^ Let the engine idle (throttle fully closed and with all electrical items oft) for 10 minutes.