TorqueMech OBD Code Guide
P0804 - 1-4 Upshift (Skip Shift) Lamp Control Circuit Malfunction
The PCM detected a fault in this control circuit or sensor input, usually caused by a failed component, wiring problem, or an out-of-range system condition.
Code first. Confirm symptoms and checks before pricing parts.
Read code pattern
Check likely system
Estimate after confirmation
Code Overview
The PCM detected a fault in this control circuit or sensor input, usually caused by a failed component, wiring problem, or an out-of-range system condition.
Common Causes
- Failed sensor or actuator
- Wiring or connector issue
- Poor power or ground
- Control-module fault
Diagnostic Steps
- Inspect the connector and harness closely
- Verify power, ground, and reference voltage
- Compare scan data to expected operation
- Check for companion codes that point to the root cause
Related OBD Codes
Browse nearby codes when systems overlap.
Next Steps
Move from code to checks, then estimate.