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 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

1. Inspect the connector and harness closely
2. Verify power, ground, and reference voltage
3. Compare scan data to expected operation
4. Check for companion codes that point to the root cause

Likely Repairs & Cost Guides

Use test results to confirm the fault before pricing the repair.

Related OBD Codes

Browse the closest code-family pages when the same fault pattern often shows up nearby.

Next Steps

Move from the code to a diagnosis path, then into repair pricing once the fault is confirmed.