EngineLightCodes
Powertrain code

P0702 Transmission Control System Electrical

Severity
Fix soon
Typical repair cost
$60–$1,320
Do it yourself
Shop job
Shop time
0.5–4 hours

P0702 reports an electrical fault in the transmission control system as a whole – typically the supply of the transmission actuators (solenoid supply, transmission relay, supply switch in the module) or a circuit fault not assigned to a single component.

How the engine computer detects it

No manufacturer document available to us describes it in detail; Ford's engine module list for 6.8 L E- and F-Series trucks stores it without the check engine light. If the solenoid supply is lost, transmissions usually fall back to a hydraulic limp gear. Individual solenoids have their own codes (P0750 ff); actuator supply is P0657 ff.

Written from public technical sources and not yet checked by a mechanic. How we write these pages

Symptoms

  • Transmission limp mode with fixed gear
  • Transmission warning; check engine light depending on the maker
  • No or harsh shifts, further solenoid codes

Common causes

  1. Transmission actuator supply interrupted (fuse, relay, ground) Most likely
  2. Harness or connector at transmission or module damaged, corroded or oil-soaked Possible
  3. Transmission module output stage or supply switch faulty Possible
  4. Low or fluctuating system voltage Less likely

How to diagnose P0702

  1. Read every stored code with an OBD-II scanner. If misfire or fuel trim codes are there too, fix those first: they often cause this one.
  2. Inspect the parts involved: transmission control module, transmission solenoid supply, transmission wiring.
  3. Work through the causes above from most to least likely, cheapest checks first.
  4. Clear the code and drive a full drive cycle to confirm the repair held.

Reading the code

P
Powertrain
0
Generic (SAE) code
7
Transmission
02
Specific fault

Questions drivers ask

Can I drive with code P0702?

If the car shifts normally, drive gently to a shop. If it's stuck in one gear, slips, shifts harshly or won't move out of Park, don't drive it: have it towed.

This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.