Transmission Fluid Pressure Sensor Circuit Intermittent
The P0874 code indicates that the powertrain control module (PCM) has detected an intermittent signal from the transmission fluid pressure sensor or its circuit. This sensor monitors hydraulic pressure inside the transmission to ensure proper shift timing and line pressure. An intermittent fault means the signal is erratic or drops out temporarily, which can cause transmission shifting issues, harsh engagement, or limp mode. Common causes include a faulty sensor, damaged wiring or connectors, low transmission fluid, or internal transmission problems.
01. Most Common Causes
- Faulty transmission fluid pressure sensor
- Damaged or corroded wiring/connectors in the sensor circuit
- Low or contaminated transmission fluid
- Internal transmission mechanical failure
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Erratic or harsh shifting
- Transmission slipping or delayed engagement
- Transmission stuck in limp mode (e.g., 2nd gear only)
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data to capture conditions when the fault occurred.
Step 2: Inspect transmission fluid level and condition; top off or replace if necessary.
Step 3: Visually check the sensor connector and wiring for damage, corrosion, or loose connections.
Step 4: Use a multimeter to test sensor resistance and voltage supply per manufacturer specs; compare with known good values.
Step 5: If sensor and circuit check out, perform a transmission pressure test to rule out internal issues.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances with P0874, as intermittent pressure loss can cause transmission damage. If the transmission goes into limp mode, you may lose high gears and overdrive, but you can drive cautiously to a repair shop.
How much does it cost to fix?▼
Repair costs typically range from $150 to $400, depending on the cause. A sensor replacement is usually $150-$250, while wiring repairs or fluid changes may be less. Internal transmission repairs can exceed $1,000.