OBD-II Fault Code

C1748: Switch input Circuit Short to Gnd

Meaning, symptoms, likely causes, diagnostic checks and repair guidance for C1748.

System family

Chassis

Manufacturer-specific

Repair category

Electrical circuit / sensor

Use this category to narrow your checks before replacing parts.

Severity

Medium

Severity is a general guide. Confirm with scan-tool data and vehicle symptoms.

What C1748 usually means

Switch input Circuit Short to Gnd.

Common symptoms

ABS/traction/steering/suspension warning lamp or abnormal chassis behaviour

Likely causes

Faulty related sensor/actuator; Wiring or connector issue; Poor ground/power supply; Control module fault is possible but less common

Diagnostic checks

Inspect wheel/brake/suspension area, connectors, sensor wiring and module power/ground

Repair guidance

Repair wiring/connector/fuse issues first; Replace the related sensor/actuator only after testing confirms failure; Use OEM service manual for brand-specific procedures

Verification after repair

Clear code, road-test safely at low speed first, then rescan

Note: Confirm vehicle make/model/year because manufacturer-specific codes can vary; Manufacturer-specific: confirm definition and test steps in the vehicle service manual. A DTC identifies a circuit or system condition, not always the failed part.