P0375
Timing Reference High Resolution Signal B MalfunctionP0375 is a generic OBD-II powertrain diagnostic trouble code: Timing Reference High Resolution Signal B Malfunction. It is logged by the engine control unit when the powertrain monitor detects that a specific fault threshold has been exceeded — typically resulting in the malfunction-indicator lamp (MIL / check-engine light) being illuminated.
What P0375 means
P0375 — "Timing Reference High Resolution Signal 'B' Malfunction" — is stored when the PCM detects a general malfunction in the second high-resolution engine position reference channel. The 'B' designation indicates the secondary channel, which is physically separate from the channel A signal described by the P037x series: on certain multi-cylinder platforms, channel B is provided by a second reluctor ring on the opposite camshaft, or serves as a backup/redundant reference that the PCM cross-checks against channel A to validate timing accuracy.
This architecture is found on specific platforms including certain Ford modular engines, BMW high-precision camshaft phaser systems (where each camshaft has its own high-resolution encoder), and some GM diesel applications using dual pickup sensors. The 'B' channel is not fitted to all vehicles — P0375 will only appear on platforms where the PCM is programmed to expect and monitor two independent high-resolution references. On such platforms, loss of the B channel degrades timing accuracy or cam phaser feedback, even if the engine continues to run using channel A as primary.
P0375 is the general malfunction code for channel B; the sub-variants P0376 (too many pulses) and P0377 (too few pulses) are more specific. When the PCM detects any abnormal condition — absent signal, wrong count, wrong frequency, or out-of-range voltage — without narrowing it to a specific count error, P0375 is stored. Diagnosis parallels the channel A approach: inspect the channel B sensor, its wiring, and the channel B reluctor ring, then use an oscilloscope to characterize the fault.
Common causes
Most-frequently reported root causes when P0375 is logged.
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1
Faulty channel B crankshaft or camshaft position sensor with degraded output.
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2
Open circuit, short to ground, or short to voltage on the channel B sensor signal wire.
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3
Corroded, damaged, or loosely seated connector at the channel B sensor.
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4
Damaged channel B reluctor ring (broken or missing teeth, separated ring).
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5
Excessive sensor-to-ring air gap on the channel B sensor.
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6
Hall-effect element contaminated with metallic debris on the B-channel sensor tip.
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7
Loss of 5V reference or sensor ground on the channel B circuit.
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8
PCM input circuit fault on the channel B high-resolution signal pin.
Symptoms drivers notice
How to diagnose P0375
A typical diagnostic flow when this code is present.
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1
Retrieve all stored codes; note concurrent P0376/P0377 (channel B count codes), P0370/P0371 (channel A count codes), or cam phaser codes that provide additional fault context.
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2
Identify the channel B sensor location on the specific vehicle platform — on dual-cam phaser engines it is typically the second camshaft position sensor; on others it may be a dedicated crankshaft high-resolution pickup.
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3
Inspect the channel B sensor connector and wiring harness for corrosion, loose pins, and damage.
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4
Measure 5V reference voltage, ground continuity, and signal circuit continuity at the channel B sensor connector with a digital multimeter.
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5
Use an oscilloscope on the channel B signal wire during cranking or at idle to characterize the fault — check for no signal, irregular spacing, or abnormal amplitude.
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6
Inspect the channel B reluctor ring for missing, cracked, or damaged teeth.
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7
Verify sensor air gap against manufacturer specification.
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8
Replace the channel B sensor after confirming wiring integrity; retest across a full drive cycle.
Related powertrain codes
Frequently asked questions
What vehicles have a channel B high-resolution timing reference?
P0375 applies to specific platforms including certain Ford modular V8 engines (EEC-V), BMW engines with dual high-precision camshaft phaser encoders, and some GM 6.5L Stanadyne diesel applications. Not all vehicles are equipped with a channel B reference — the code only appears on PCM calibrations that actively monitor a second high-resolution input.
Is P0375 the same fault as P0370 on channel A?
Structurally yes — P0375 is the channel B equivalent of P0370 (channel A general malfunction). The sensor hardware, circuit layout, and diagnostic approach are identical; only the physical sensor location and PCM input pin differ.
Can the engine run normally with only channel A active if channel B fails?
On many platforms yes — the PCM falls back to channel A as the primary reference and may limit cam phaser activity on the cylinder bank or camshaft associated with channel B. Engine performance may be noticeably degraded, particularly at high RPM, but a complete no-start is uncommon unless channel B is the sole reference source on that variant.
Will replacing the channel A sensor fix P0375?
No. P0375 specifically relates to the channel B circuit. The sensors are physically separate components on different locations of the engine. Confirm the channel B sensor location for the specific vehicle before purchasing a replacement.
Disabling P0375 in software
RaceTune can permanently disable P0375 — and any other OBD-II diagnostic trouble code — on every ECU family we support. The monitor is disabled inside the ECU itself, so the fault stops being logged: the warning light stays off and the engine never enters limp mode for this code. The change is tied to your exact software version.
Software modifications affect emissions compliance and are not road-legal in many jurisdictions. RaceTune service files are intended for motorsport, off-road, and export use.
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