P0702
Transmission Control System Electrical
- Severity
- High
- Driving
- Drive only to a garage
An electrical fault has been found in the transmission control system - the wiring, a connector, or a component circuit rather than the mechanical transmission. The module has usually dropped into a failsafe mode, which typically means one fixed gear and no shifting, so the car will move but very badly.
Possible causes
- CommonDamaged or corroded transmission connector - the main case connector is a common failure point
- CommonFailed internal wiring harness inside the transmission
- CommonFluid wicking up the harness into the connector or the module
- PossibleBlown fuse or poor earth on the transmission module supply
- PossibleFailed solenoid or sensor
- RareFailed transmission control module
What you might notice
- Transmission stuck in one gear
- No shifting at all
- Harsh engagement
- Several transmission codes stored together
- Check engine light on
What to check, in order
- Read all transmission codes together. Several electrical codes at once point at a shared cause - the case connector, the internal harness or the power supply - not at several failed parts.
- Inspect the main transmission case connector. Pull it and look for fluid inside, corroded pins and green residue. Fluid wicking through the harness is a classic cause and it also destroys the module it reaches.
- Check the fuses and earths for the transmission module.
- Check the fluid level and condition.
- Do not order a control module until the connector and internal harness have been eliminated. Modules are expensive and usually innocent.
Read this code from your own car
Plug an ELM327 adapter into the OBD-II port under the dashboard. Pin16 reads every stored, pending and permanent code, explains each one like this page does — offline, with no account — and shows what the car recorded when the fault was set.
Where this code sits
P00xxP01xxP02xxP03xxP04xxP05xxP06xxP07xxP08xxP09xxP0AxxP0BxxP0CxxP0DxxP0ExxP0FxxP10xxP11xxP12xxP13xxP14xxP15xxP16xxP17xxP18xxP19xxP1AxxP1BxxP1CxxP1DxxP1ExxP1FxxP20xxP21xxP22xxP23xxP24xxP25xxP26xxP27xxP28xxP29xxP2AxxP2BxxP2CxxP2DxxP2ExxP2FxxP30xxP31xxP32xxP33xxP34xxP35xxP36xxP37xxP38xxP39xxP3AxxP3BxxP3CxxP3DxxP3ExxP3Fxx
Transmission
P0700P0701P0702P0703P0704P0705P0706P0707P0708P0709P0710P0711P0712P0713P0714P0715P0716P0717P0718P0719P0720P0721P0722P0723P0724P0725P0726P0727P0728P0729P0730P0731P0732P0733P0734P0735P0736P0737P0738P0739P0740P0741P0742P0743P0744P0745P0746P0747P0748P0749P0750P0751P0752P0753P0754P0755P0756P0757P0758P0759P0760P0761P0762P0763P0764P0765P0766P0767P0768P0769P0770P0771P0772P0773P0774P0775P0776P0777P0778P0779P0780P0781P0782P0783P0784P0785P0786P0787P0788P0789P0790P0791P0792P0793P0794P0795P0796P0797P0798P0799