OBD-II Fault Code

P1398: VVT Solenoid B Circuit High Input

Meaning, symptoms, likely causes, diagnostic checks and repair guidance for P1398.

System family

Powertrain

Manufacturer-specific

Repair category

Engine timing / position

Use this category to narrow your checks before replacing parts.

Severity

High

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

What P1398 usually means

VVT Solenoid B Circuit High Input.

Common symptoms

Check Engine light; Poor drivability or reduced fuel economy depending on fault; No-start, rough running, limp mode or poor power possible

Likely causes

Faulty cam/crank sensor; Oil level/quality issue; VVT solenoid fault; Timing chain/belt issue; Wiring fault; High signal voltage; Open ground; Short to voltage; Failed sensor

Diagnostic checks

Scan all modules and record freeze-frame data before clearing codes; Check battery voltage and related fuses; Check oil level/condition; Inspect sensor/solenoid connectors; Compare cam/crank correlation with scan data; Check sensor ground and signal circuit for short to voltage

Repair guidance

Repair wiring or replace confirmed failed sensor/solenoid; Investigate mechanical timing if correlation faults remain; Repair ground/signal circuit or replace confirmed faulty sensor

Verification after repair

Clear code, road-test through the same drive condition, 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.