P2738: Pressure Control Solenoid 'H' Control Circuit Low
The Powertrain Control Module (PCM) has detected a low voltage condition in the control circuit of the pressure control solenoid 'H'. This solenoid is typically used in automatic transmissions to regulate hydraulic pressure for clutch and band application. A low circuit voltage indicates a short to ground, open circuit, or faulty solenoid, which can lead to improper transmission operation.
01. Most Common Causes
- Faulty pressure control solenoid 'H'
- Open or shorted wiring in the solenoid control circuit
- Poor electrical connection at the solenoid or PCM
- Failed PCM (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Harsh or erratic shifting
- Transmission slipping or stuck in gear
- Reduced fuel economy
03. Step-by-Step Diagnosis
Step 1: Use a scan tool to retrieve all codes and freeze frame data.
Step 2: Inspect the transmission wiring harness and connectors for damage, corrosion, or loose pins.
Step 3: Measure resistance of the pressure control solenoid 'H' and compare to manufacturer specs (typically 4-6 ohms).
Step 4: Check for voltage and ground at the solenoid connector with the ignition on; if missing, repair wiring or replace PCM.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. Driving with a low circuit code can cause transmission damage due to improper pressure control.
How much does it cost to fix?▼
Repair costs range from $150 to $400, depending on whether the solenoid, wiring, or PCM needs replacement.