P1550moderate severityPowertrain

TCC Solenoid Valve

on 2002 Infiniti QX4 3.3L V6 · RWD

What this code means

Fault in torque converter clutch solenoid for converter lockup.

Symptoms

  • CEL
  • No TCC lockup
  • Poor highway fuel economy
  • Shudder at cruise
  • RPM flare

Common causes

  • Faulty TCC solenoid
  • Damaged wiring
  • Contaminated fluid
  • Faulty TCM

Diagnostic steps

  1. Test solenoid resistance
  2. Check fluid condition
  3. Inspect connector
  4. Monitor with scan tool

Repair notes

Replace TCC solenoid.

Other Powertrain codes on this vehicle

⚠ STILL BEHIND THE PAYWALL
The 2002 Infiniti QX4 repair data is incomplete because no one has sponsored it yet. For $99, we generate the full step-by-step procedures, then fact-check them with a second AI pass and your expert review. Your name on every procedure, permanently.
The same data would cost $169/mo from Mitchell1 or $30/year from ALLDATAdiy — and you'd be renting access, not freeing it. Sponsor once, free forever.
Sponsor the Infiniti QX4 — $99 →
Building an app?
Free API access to all this data — 50 requests/day, no card required.
Get an API key →
Run a shop?
Manage repairs, estimates, and customers with ShopBase — $249/mo, all features included.
Try ShopBase →