JDM D17A CVT Transmission Jerking Issue - Need Expert Advice

Vehicle Details:

• 1997 Honda Civic
• Swapped with Civic 2002-2005 JDM D17A 1.7L engine with CVT (SLYA transmission)
• Complete engine and harness swap recently performed
• ECU 37820-PLE-J81

The Problem

I'm experiencing intermittent jerking issues with my freshly swapped JDM D17A CVT setup, and I'm trying to determine if this is a transmission problem or something else entirely.

Symptoms

When the jerking occurs:

• Most commonly happens after coasting - when I accelerate to 100 km/h, release the throttle to slow down, then try to accelerate again but sometimes it start to happen at low speeds as well without even touching high kms
• Jerking is particularly noticeable at low speeds after the deceleration scenario above
• The issue is intermittent - sometimes it happens, sometimes it doesn't
• It occurs "very often" but not 100% of the time

When the car runs fine:

• Hard throttle acceleration - the car accelerates properly without any jerking or hesitation
• No issues during aggressive driving or full throttle

What I've Already Done

• ✅ Complete JDM engine swap (D17A with CVT)
• ✅ Replaced with complete JDM engine harness
• ✅ Checked for CEL - No check engine light present
• ✅ Checked CVT fluid - no burning smell, proper level
• ✅ OBD scan performed

Diagnostic Findings

Major concern: When scanning with OBD, the transmission doesn't communicate properly:

• OBD doesn't detect CVT transmission parameters
• Shows "0" values for all transmission-related data
• Can't identify whether it's reading CVT or ATF transmission type
• Essentially no transmission data available through OBD

Local Mechanic Opinion

Local mechanics are suggesting it's a bad transmission, but I want to explore all possibilities before replacing or rebuilding the CVT unit.

Additional Information Needed

If anyone has experience with this issue, I'd appreciate knowing:

• Should I be checking specific sensors (vehicle speed sensor, transmission range sensor, etc.)?
• Are there known issues with JDM D17A CVT swaps and OBD communication?
• What diagnostic steps should I take before condemning the transmission?
• Could this be related to the CVT learning/adaptation process after the swap?

I really want to avoid pulling and replacing the transmission if it's actually a sensor, wiring, or ECU issue. Any guidance from those familiar with Honda CVT transmissions or JDM swaps would be greatly appreciated.

Thanks in advance for any help!

 

Your AI post sucks. Nobody would swap an automatic d17 into a 97 civic.

 

No need to go harsh its very common practice in my country people often swapping D17A in 97 because we have very limited options to choose from. Also, why wouldn’t you want to swap it? It’s a direct bolt on upgrade there’s really no reason not to.

 

Sorry buddy I wasnt sure it was a real post. We have no need here to swap such a poor performing engine and transmission in most markets. You likely have an issue with the transmission not matching the ecu. You cannot mix engine, transmission or ecu with automatics, they must all match. It sounds like you have a non jdm ecu.

 

English is my second language which is why i have to express myself with AI assistance. this guy might be like me. why do you care whether someone writes in AI or not just answer the question and provide helpful feedback instead of ridiculing people for using AI. (were not writing college papers here)

 

Jerking can be related to CVT pressure or speed signal issue, not internal damage. Before remove transmission, check if youir wiring and ECU match first

 

It's not about ridiculing them or you, it's about if the poster is an actual live human.