OBD-II code · Powertrain (generic)
P0802 Transmission Control System MIL Request Circuit/Open
The dedicated MIL request line from the TCM to the ECM (used in older systems where modules used a hard wire to ask for the MIL instead of CAN messaging) is open. The ECM cannot honour TCM-side MIL requests.
Is it safe to drive with P0802?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyOpen MIL request wire
- Less likelyPin pushed back out of connector body
- Less likelyCracked solder joint inside the module or sensor
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.4–1.5 h
- Emissions test
- Usually unaffected
- Parts involved
- Mil Request Wire, Tcm, Ecm
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.