Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
PCM Replacement
Special Tools Required
- Honda Diagnostic System (HDS) tablet tester
- Honda Interface Module (HIM) and an iN workstation with the latest HDS software version
- HDS pocket tester
- GNA600 and an iN workstation with the latest HDS software version
- MVCI unit with the latest control module (CM) update software installed
Any one of the above updating tools can be used.
- Make sure the HDS/iN workstation or the MVCI has the latest HDS software version.
- If you are replacing the PCM after substituting a known-good PCM, reinstall the original PCM, then do this procedure.
- During the procedure, if any READ DATA, WRITE DATA, or other data checks fail, note the failure, then continue.
- Connect the HDS to the data link connector (DLC) (A) located under the driver's side of the dashboard.
- Turn the ignition switch to ON (II).
- Make sure the HDS communicates with the PCM and other vehicle systems. If it doesn't, go to the DLC CIRCUIT TROUBLESHOOTING
. If you are returning from DLC circuit troubleshooting, skip steps 4 through 9, 20 through 26, and 29 through 31, and do this after replacing the PCM;
- Replace the engine oil (see OIL PRESSURE TEST ) and the engine oil filter (see ENGINE OIL FILTER REPLACEMENT ).
- Replace the ATF (see ATF REPLACEMENT ).
- Clean the throttle body (see THROTTLE BODY TEST ).
- Select the PGM-FI system with the HDS.
- Select the INSPECTION MENU with the HDS.
- Select the ETCS TEST, then select the TP POSITION CHECK, and follow the screen prompts.NOTE: If the TP POSITION CHECK indicates FAILED, continue with this procedure.
- Select the REPLACE PCM MENU, then select READ DATA and follow the screen prompts.NOTE:
- Doing this step copies (READS) the engine oil life data from the original PCM so you can later download (WRITES) it into the new PCM.
- If the READ DATA indicates FAILED, continue with this procedure.
- Select the A/T system with the HDS.
- Select the REPLACE TCM/PCM MENU, then select READ DATA and follow the screen prompts.NOTE:
- Doing this step copies (READS) the ATF life data from the original PCM so you can later download (WRITES) it into the new PCM.
- If the READ DATA indicates FAILED, continue with this procedure.
- Turn the ignition switch to LOCK (0).
- Jump the SCS line with the HDS.
- Remove the auxiliary under-hood fuse/relay box (A) from the stay (B), then remove the bolt (C).
- Remove the bracket (D), then free the A/C discharge line (E) from the clip (F) and remove the A/C suction line mounting bracket bolt (G).
Keihin PCM
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Continental PCM
- Remove the cover (H), then disconnect PCM connectors A, B, and C.NOTE: PCM connectors A, B, and C have symbols (A=□, B=Δ , C=◦) embossed on them for identification.
- Keihin PCM: Remove the bolts (I), then remove the PCM (J).
- Continental PCM: Remove the nuts (K), then remove the PCM (J).
- Continental PCM: Remove the spacers (L).
- Install the parts in the reverse order of removal.
- Turn the ignition switch to ON (II).
- Manually input the VIN to the PCM with the HDS.NOTE: DTC P0630 VIN Not Programmed or Mismatch may be stored because the VIN has not been programmed into the PCM; ignore it, and continue this procedure.
- If the READ DATA (engine oil life) failed in step 7, go to step 24. Otherwise, go to step 22.
- Select the PGM-FI system with the HDS.
- Select the REPLACE PCM MENU, then select WRITE DATA and follow the screen prompts.NOTE: If the WRITE DATA indicates FAILED, continue with this procedure.
- If the READ DATA (ATF life) failed in step 9, go to step 27. Otherwise go to step 25.
- Select the A/T SYSTEM with the HDS.
- Select the REPLACE TCM/PCM MENU, then select WRITE DATA and follow the screen prompts.NOTE: If the WRITE DATA indicates FAILED, continue with this procedure.
- Select IMMOBI SYSTEM with the HDS.
- Enter the immobilizer PCM code that you got from the iN, and use the PCM replacement procedure in the IMMOBI MENU of the HDS; it allows you to start the engine.
- If the TP POSITION CHECK failed in step 6, clean the throttle body (see THROTTLE BODY TEST ), then go to step 30.
- If the READ DATA failed in step 7 or the WRITE DATA failed in step 23, replace the engine oil (see OIL PRESSURE TEST ) and engine oil filter (see ENGINE OIL FILTER REPLACEMENT ), then go to step 31.
- If the READ DATA failed in step 9 or the WRITE DATA failed in step 26, replace the ATF (see ATF REPLACEMENT ), then go to step 32.
- Select PGM-FI system and reset the PCM with the HDS.
- Update the PCM if it does not have the latest software (see PCM UPDATE ).
- Do the PCM idle learn procedure (see PCM IDLE LEARN PROCEDURE ).
- Do the CKP pattern clear/CKP pattern learn procedure (see HDS CLEAR COMMAND ).
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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