What Does P252A Mean?
The PCM has detected a malfunction in the engine oil quality sensor circuit. This sensor monitors oil condition, contamination, or degradation to help determine oil change intervals.
Common Causes
45%
Faulty oil quality sensor
25%
Damaged or corroded sensor connector
15%
Broken or shorted sensor wiring harness
10%
Contaminated sensor due to sludge or debris in oil
5%
PCM internal circuit fault
Diagnostic Steps
1
Step 1: Locate and inspect the oil quality sensor (typically mounted in oil pan or engine block) and its connector
2
Step 2: Check sensor connector for oil contamination, corrosion, or damaged pins
3
Step 3: Test sensor power supply and ground circuits with a multimeter (usually 5V or 12V reference)
4
Step 4: Measure sensor resistance or signal voltage and compare to manufacturer specifications
5
Step 5: Check oil condition and contamination level; replace oil and filter if severely degraded or contaminated
Estimated Repair Cost
$150 - $400
Parts + labor, varies by vehicle and location
The PCM has detected a malfunction in the engine oil quality sensor circuit. This sensor monitors oil condition, contamination, or degradation to help determine oil change intervals.
The most common cause of P252A (Engine Oil Quality Sensor Circuit) is: Faulty oil quality sensor
Typical repair costs for P252A range from $150 to $400, depending on the vehicle, location, and whether you do it yourself or go to a shop.
No immediate safety concern. Oil life monitoring will be inaccurate, potentially leading to delayed oil changes that could affect long-term engine health.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P252A to identify the root cause.
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Quick Info
Category
Powertrain
System
Engine Oil Monitoring System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
