Code Definition

B1846 — Ignition Tamper Circuit Open

System: Body  |  Type: Manufacturer-Specific  |  Make: Ford

About B1846

B1846 is a manufacturer-specific body diagnostic trouble code recorded for Ford vehicles. It belongs to the B-prefix family of codes, which covers body, interior, airbag, or comfort-electronics faults.

When B1846 is stored, the module has detected an open (broken or disconnected) electrical path in the monitored circuit.

Scanning & clearing: Body (B) codes are often stored in the body control module, airbag module, or climate module. A basic OBD-II tool usually will not read body codes — an enhanced or OEM-level scan tool is typically required.

B1846 is a manufacturer-specific code. The same code string on a different make may have a different meaning. Always confirm the code's definition against the vehicle's service information for the specific make and model under test.

Code Information

The B1846 fault code is set by the Body Control Module (BCM) or Generic Electronic Module (GEM) when it detects an open circuit on the ignition tamper switch input. The tamper switch is part of the steering column security hardware and signals the module if the ignition lock cylinder has been disturbed. The module monitors the switch circuit by pulling it to a reference voltage and watching for the expected current return; when no current returns (open circuit), it stores B1846. The driver may notice security indicator anomalies, intermittent no start conditions accompanied by PATS codes, or n...

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