P0738
Sistema
Powertrain (Transmission)
Escáner necesario
Full-system scanner (engine, ABS, SRS, transmission, service resets)

Gear 8 Incorrect Ratio

Understand P0738, common causes, and the right FOXWELL scanner to diagnose it.

Eighth gear ratio incorrect on 8–10 speed automatics.

Síntomas habituales

  • Missing top gear
  • Reduced fuel economy

Causas típicas

  • Failed 8th gear clutch
  • TCM calibration issue
  • Low fluid
  • Solenoid sticking

¿Qué escáner necesita?

Full-system scanner (engine, ABS, SRS, transmission, service resets)

Use datos en vivo y freeze frame antes de cambiar piezas. Códigos ABS, SRS y U suelen requerir un escáner de todos los sistemas.

Consejos de diagnóstico

  • Registre el freeze frame cuando se active el código
  • Borre el código solo tras corregir la causa
  • Revise códigos pendientes relacionados
  • Verifique que la batería esté por encima de 12,4 V antes de sospechar sensores

Escáneres FOXWELL recomendados

Preguntas frecuentes

Can I diagnose P0738 with a basic code reader?
P0738 may set in the engine module, but related diagnostics often benefit from an enhanced or full-system scanner with live data and freeze frame.
Is it safe to drive with P0738?
It depends on the code and symptoms. Flashing check engine lights and misfire codes should be addressed immediately. Consult a professional if unsure.