Infiniti QX60 CVT Judder Codes with Turning Vibration – Full Diagnostic Breakdown

Introduction

Every now and then, you run into a vehicle that gives you mixed signals—the symptoms point one way, but the data tells a slightly different story. That’s exactly what happened in this case.

We had a vehicle come in with complaints of vibration during sharp turns and a rear-end noise, but what we uncovered during diagnosis added another layer: non-clearable CVT judder codes.

Let’s walk through this step-by-step the same way I approached it in the bay.

Vehicle Concern

The primary concerns were:

Vibration or “bumping” sensation during sharp turns
Noise that seemed to come from the rear of the vehicle
No obvious drivability complaints during normal acceleration

At first glance, this sounds like a rear driveline or AWD issue, not a transmission problem.

Initial Inspection & Symptoms

I started with a road test to duplicate the issue.

What I observed:

During tight turns, there was a noticeable vibration/binding sensation
It felt like it was coming from the rear end
Under normal driving conditions, the vehicle felt relatively smooth

Back in the bay, I performed a brake torque test:

Forward and reverse load applied
No significant judder, slipping, or RPM fluctuation
However, I did notice a clicking noise when shifting from forward to reverse with slight throttle

That click is important—it usually points toward driveline lash, mounts, or axle play, not internal transmission failure.

Diagnostic Trouble Codes

Next step: scan the system.

Codes retrieved:

P17F1 – CVT Judder (Control Valve)
P17F2 – CVT Judder (Torque Converter)

Here’s the key detail:

👉 These codes would not clear

That changes the entire direction of the diagnosis.

Diagnostic Process (Step-by-Step)

1. Confirm the Complaint

Always verify what the vehicle is doing before jumping to conclusions.

Road test confirmed turn-related vibration
No strong evidence of transmission failure during driving

2. Load Test the Transmission

Brake torque testing is one of the quickest ways to expose CVT issues.

What I was looking for:

Judder
RPM instability
Delayed engagement

What I found:

None of the above

👉 This told me the transmission was not actively failing under load

3. Evaluate the Clicking Noise

The click during forward/reverse transition pointed me toward:

Engine/trans mounts
CV axles (inner joints)
Driveline backlash
Transfer case slack

This is not typical CVT failure behavior

4. Analyze the Codes (Critical Step)

Now we circle back to those P17F1 and P17F2 codes.

These are not your typical “check engine light” faults.

They are:

Algorithm-based detection codes
Set when the system detects internal slip or judder over time
Often non-clearable once stored

👉 These are essentially internal wear confirmation codes

Even if the transmission feels okay now, the system has already recorded deterioration.

5. Separate Symptom vs Condition

This is where a lot of techs go wrong.

You have to separate:

What the vehicle is doing now
vs
What the system knows has happened

In this case:

The turning vibration → likely AWD/rear driveline
The stored CVT codes → confirmed internal wear

Two different issues.

6. Consider the Rear Driveline

Based on the turning symptoms, I looked at likely causes:

Rear differential fluid breakdown
AWD clutch binding
Tire mismatch
Driveline wind-up

At 100K+ miles, fluid condition alone can cause binding in turns

Key Findings

No active transmission failure during load testing
Clicking noise consistent with driveline lash
Vibration during turns consistent with AWD/rear differential behavior
P17F1 and P17F2 codes present and non-clearable
Codes indicate confirmed internal CVT wear

Final Diagnosis / Recommendation

Here’s the honest, professional conclusion:

Transmission:

Internal deterioration has been confirmed by the system
Codes will not clear
Replacement is justified based on fault status and resale requirements

Rear Driveline:

Recommend rear differential fluid service
Re-evaluate after service to determine if further repair is needed

This is the safest and most accurate approach.

Common Causes of This Issue

For CVT Judder Codes:

Internal belt and pulley wear
Torque converter clutch degradation
Valve body pressure instability
Overheated or degraded fluid

For Turning Vibration:

Rear differential fluid breakdown
AWD clutch pack binding
Mismatched tire sizes or wear
Worn CV axles or mounts

Tools Used

Professional scan tool (Autel or equivalent)
Road test evaluation
Brake torque test
Visual inspection

Tips for DIYers or Buyers

If you’re dealing with a similar situation:

1. Don’t assume it’s one problem

Multiple issues can exist at the same time.

2. Always road test first

Feel what the vehicle is doing before relying on codes.

3. Be cautious with CVT codes

Some codes indicate history, others indicate failure

4. Check the basics

Tires and fluid condition can cause major symptoms.

5. Non-clearable codes matter

If a code won’t clear, it’s there for a reason.

When to Refer to a Professional

If you see CVT judder codes like these and aren’t sure how to interpret them, this is where experience matters.

Misdiagnosing this could mean:

Replacing a transmission unnecessarily
or
Missing a failing unit entirely

Conclusion

This was a great example of why diagnostics isn’t just about plugging in a scan tool—it’s about understanding how symptoms, data, and system logic all connect.