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.
ECM/PCM Replacement
Special Tools RequiredÂ
- 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.
- Connect HDS to the data link connector (DLC) (A) located under the driver's side of the dashboard.
- Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
- Make sure the HDS communicates with the ECM/PCM and other vehicle systems. If it doesn't, go to the DLC CIRCUIT TROUBLESHOOTINGÂ
. If you are returning from the DLC circuit troubleshooting, skip steps 4 through  9,  18 through  23, and  26 through  28, and do this after replacing the ECM/PCM:
- Replace the engine oil (see ENGINE OIL REPLACEMENT ) and the engine oil filter (see ENGINE OIL FILTER REPLACEMENT ).
- Replace the ATF (A/T) (see ATF REPLACEMENT ).
- Clean the throttle body (see THROTTLE BODY CLEANING ).
- 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 ECM/PCM so you can later download (WRITES) it into the new ECM/PCM.
- If READ DATA indicates FAILED, continue with this procedure.
- A/T: Select the A/T system with the HDS.
- A/T: 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 READ DATA indicates FAILED, continue with this procedure.
- Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
- Jump the SCS line with the HDS.
- Canada model: If equipped, remove the ECM/PCM connector guard (A).
- Disconnect ECM/PCM connectors A, B, and C, then remove the ECM/PCM assembly (D).NOTE: ECM/PCM connectors A, B, and C have symbols (A=□, B=Δ, C=◦) embossed on them for identification.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
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.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
No obligation. See pricing before you book.
