What does P1156 mean on a Ford?

P1156. Fuel Selector Switch Circuit Fault. Applies to Bi-fuel CNG/propane Ford trucks and vans.

What causes P1156 on a Ford?

Failed fuel selector switch Open or shorted switch circuit Corroded switch connector Faulty selector indicator Controller input fault

How do I fix P1156 on a Ford?

Test switch continuity in each position Inspect the switch connector Check circuit wiring to the controller Verify the indicator matches actual fuel mode Replace the switch if the circuit is sound

Code

P1156

Fuel Selector Switch Circuit Fault

Category: Powertrain - Fuel/Air Metering
Severity: Check Engine Light
Applies to: Bi-fuel CNG/propane Ford trucks and vans
Related: No single generic twin. See OBD Codes List

Findings, check these first

Failed fuel selector switch
Open or shorted switch circuit
Corroded switch connector
Faulty selector indicator
Controller input fault

Standard procedure

Test switch continuity in each position
Inspect the switch connector
Check circuit wiring to the controller
Verify the indicator matches actual fuel mode
Replace the switch if the circuit is sound

Code lookup

Type a code above, or start from a symptom or a common code.

Press / to jump to the box. Ford-enhanced powertrain, body, chassis and network codes. Generic P0xxx codes live on OBD Codes List.

Sources and review

Review: checked against the recorded source material.

OBDII.pro: P1156 Ford definition
live reference page (obdii.pro)
Supports: Ford-family meaning for P1156: Fuel Select Switch Malfunction
Fetched directly. obdii.pro is a publisher independent of the engine-codes family.
P1156 FORD Code: Meaning, Causes, and Symptoms | OBD2 Codes
live reference page (obd2-codes.co)
Supports: Ford meaning for P1156: Fuel Selector Switch Circuit
Fetched directly. obd2-codes.co phrasing matches the engine-codes family, so it counts as one publisher.

Last updated 2026-09-05.

Report a correction for P1156. Include your vehicle, the issue and a source if you have one.