P0372: Timing Reference High Resolution Signal A Too Few Pulses
The PCM has detected that the high-resolution crankshaft position sensor (signal A) is providing fewer pulses than expected. This sensor is critical for precise engine timing and misfire detection. The code sets when the PCM sees an intermittent or missing signal from the sensor, often due to a faulty sensor, damaged reluctor ring, or wiring issues.
01. Most Common Causes
- Faulty crankshaft position sensor
- Damaged or missing reluctor ring teeth
- Wiring or connector issues (shorts, opens, corrosion)
- Excessive crankshaft endplay or bearing wear
- PCM failure (rare)
02. Symptoms You Will Notice
- Check Engine Light on
- Engine misfire or rough idle
- Hard starting or no start
- Reduced engine power or stalling
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect the crankshaft position sensor and reluctor ring for damage or debris.
Step 3: Test sensor resistance and AC voltage output while cranking (should be 0.5-5V AC).
Step 4: Check wiring and connectors for continuity, shorts, and corrosion.
Step 5: If sensor and wiring are good, inspect reluctor ring for missing or damaged teeth.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
No, it is not safe. The engine may stall or fail to start, and driving could cause further damage or a safety hazard.
How much does it cost to fix?▼
Typically $50-$150 for a sensor replacement, but costs can be higher if wiring repairs or reluctor ring replacement is needed.