P0701, P0702, P0802, P0898 and P0899: transmission control system and warning light request
The gearbox computer reports a performance or electrical fault in its control system, or the circuit it uses to ask the engine computer to light the engine warning light is open, low or high.
SeverityModerateUsually not urgent today, but it can get worse if left.
Can you keep driving?Drive gently, check it soonWhat does P0701 mean?
On many cars the gearbox computer cannot light the engine warning light itself; it sends a request to the engine computer, which stores P0700 or a code from this group. P0701 and P0702 are general: something in the gearbox control system is out of range or has an electrical fault, and the detail sits in the gearbox computer's own memory. P0802, P0898 and P0899 say the request line itself is broken, so a real gearbox fault might go unreported.
What causes P0701?
- A fault stored in the gearbox computer that the engine computer can only summarize
- A low supply voltage or a poor ground at the gearbox computer
- A damaged wire in the request circuit between the two computers
- A gearbox computer that needs a software update
What to check first for P0701
- Read the gearbox computer with a tool that reaches it, not only a basic code reader
- Check the battery, the grounds and the gearbox computer's supply
- Inspect the wiring and connectors between the gearbox and engine computers
- Ask whether the maker has a software update for these codes
Can you drive with P0701?
Usually you can drive to a workshop if the gearbox changes normally. If it holds one gear or changes harshly, drive gently and avoid fast roads; have it towed if it will not select a gear.
Clear a code only after the fault is fixed. A code that comes back means the cause is still there, and a warning light left on can hide a second fault behind the first.
Codes on this page
- P0701Transmission Control System Range/Performance
- P0702Transmission Control System Electrical
- P0802Transmission Control System MIL Request Circuit/Open
- P0898Transmission Control System MIL Request Circuit Low
- P0899Transmission Control System MIL Request Circuit High
Related codes
Checked on · Rafael Soares
These are the generic meanings every manufacturer shares. Each brand adds its own detail, so your car's handbook, its service information and a qualified mechanic have the last word. OdoKeep has no connection with any manufacturer, and the app does not read codes from the car.
