OBD-II Code P1700 — What It Means & How to Fix It

What Does This Error Mean?

P1700 is a transmission-related code seen on Nissan, Infiniti, and some Ford/Mazda vehicles. On Nissan and Infiniti, it means a malfunction was detected in the transmission control system. The TCM has detected an internal fault or a fault in a monitored transmission circuit. You may experience harsh or erratic shifting, transmission slipping, or the transmission stuck in one gear. Professional diagnosis is strongly recommended for this code.

Affected Models

Common in Nissan Altima, Maxima, and Murano
Common in Nissan Frontier, Pathfinder, and Xterra
Common in Infiniti G35, G37, and FX35
Seen in some Ford and Mazda models with shared platforms

Common Causes

Faulty transmission shift solenoid causing incorrect gear engagement
Low or contaminated transmission fluid reducing hydraulic pressure
Faulty transmission speed sensor sending incorrect data to the TCM
Internal TCM malfunction or software fault
Damaged wiring harness to the transmission — common due to heat and vibration

How to Fix It

Check the transmission fluid level and condition. Pull the dipstick or use the check plug depending on your vehicle.

Dark brown or burnt-smelling fluid indicates contaminated fluid that needs immediate changing.
Retrieve all stored codes using a scan tool that accesses the TCM module specifically.

P1700 often appears with companion codes that identify the specific failed component.
Inspect the wiring harness running to the transmission for chafing, cuts, or melted insulation.

Transmission harness damage is common, especially on trucks where the harness runs near hot exhaust components.
Have the transmission speed sensors tested with a live data scanner while driving.

A speed sensor that drops out intermittently is a common cause and shows up clearly in live data.
If fluid and wiring are good, have the shift solenoids and valve body tested or inspected by a transmission specialist.

Shift solenoids can be tested for resistance with a multimeter — consult the factory spec for your vehicle.

When to Call a Professional

Shift solenoid replacement is $100 to $300 depending on location. Transmission fluid service is $80 to $150 at a shop. TCM replacement can cost $200 to $600 plus programming. A full transmission rebuild, if needed, is $1,500 to $3,500.

Frequently Asked Questions

Is it safe to drive with P1700?

It is not recommended for extended driving. Harsh shifting or the transmission getting stuck in gear can leave you stranded or cause further transmission damage. Drive only as needed to get to a repair shop.

Can a transmission fluid change fix P1700?

Sometimes, yes. If contaminated or low fluid is the root cause, a fresh fluid change can restore normal operation. However, if a solenoid or sensor has already failed, a fluid change alone will not fix the code.

Does P1700 mean I need a new transmission?

Not necessarily. Many P1700 cases are resolved by replacing a shift solenoid, speed sensor, or fixing a wiring issue. Full transmission replacement is only needed if there is significant internal mechanical damage. Get a full diagnosis before assuming the worst.