P1747 - EPC Solenoid Short Circuit
The P1747 code indicates a short circuit in the Electronic Pressure Control (EPC) solenoid circuit. The EPC solenoid regulates transmission line pressure based on engine load and throttle position. A short circuit can cause erratic shifting, harsh engagement, or transmission slippage. This code is often triggered by damaged wiring, a faulty solenoid, or a failed transmission control module (TCM).
1. Symptoms You Will Notice
- Check Engine Light or Transmission Warning Light illuminated
- Harsh or delayed shifts
- Transmission slipping or stuck in gear
- Reduced fuel economy
2. Most Common Causes
- Shorted or damaged wiring in the EPC solenoid circuit
- Faulty EPC solenoid
- Corroded or loose electrical connectors
- Failed transmission control module (TCM)
3. Step-by-Step Diagnosis
Step 1: Scan the vehicle for codes and record freeze frame data.
Step 2: Visually inspect the EPC solenoid wiring and connectors for damage, corrosion, or loose connections.
Step 3: Measure resistance of the EPC solenoid; compare to manufacturer specifications (typically 3-7 ohms).
Step 4: Check for short to ground or power in the solenoid circuit using a multimeter.
Step 5: If wiring and solenoid are okay, test the TCM output signal; replace TCM if faulty.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. Driving with a shorted EPC solenoid can cause erratic shifting, transmission damage, or complete failure. Have it diagnosed and repaired promptly.
How much does it cost to fix?▼
Repair costs vary. Replacing the EPC solenoid typically costs $150-$300, including parts and labor. If the TCM needs replacement, costs can exceed $400.
5. Commonly Affected Makes
This is a manufacturer-specific code. The exact manufacturer is not confirmed in our current database.