P0804
1-4 Upshift Skip Shift Lamp Control Circuit Malfunction
Generic code
Transmission System
High severity
Hard repair
Free on OBD DashX
Want real-world data on P0804?
See which problems come with P0804, how often it shows up in other vehicles, and how to fix it — step by step.
- Real-world fix data
- How often it happens
- Step-by-step repairs
What P0804 means
- The fault code P0804 indicates that there is an issue with the circuit that controls the upshift (skip shift) lamp. This circuit is responsible for indicating the driver to change gears when accelerating. This fault code may cause the upshift lamp to perform improperly or not at all.
Possible symptoms
- Upshift (skip shift) lamp not illuminating
- Illuminated check engine light
- Delayed or improper shifting
- Reduced fuel efficiency
Possible causes
- Failed upshift lamp control module
- Faulty wiring or connections in the circuit
- Loose or corroded electrical connections
- Failed transmission control module (TCM)
Related parts
- Transmission Shift Sensor: Gear Shift Sensor communicates the position the gear shifted to. Problems lead to difficulty in shifting gears
Possible solutions
- Replace the upshift lamp control module
- Check and repair any damaged wiring or connections
- Tighten or clean any loose or corroded electrical connections
- Replace the transmission control module (TCM) if necessary
Free on OBD DashX
P0804 on OBD DashX
Real-world causes, how often this code shows up, and the fix — step by step.
Open P0804 No sign-up needed · available in 10 languagesScan your own car
Read and clear fault codes, live data and service resets with the CaRPM app.