Glow Plug Circuit Low Input Bank #2 (Left)
The P1393 code indicates that the powertrain control module (PCM) has detected a low voltage condition in the glow plug circuit for bank #2 (left side of the engine). This typically means the glow plugs are not receiving enough power to properly heat the combustion chambers, which can cause hard starting, misfires, and increased emissions, especially in cold weather. The issue is often due to a faulty glow plug, damaged wiring, or a failing glow plug relay.
01. Most Common Causes
- Faulty glow plug(s) in bank #2
- Open or shorted wiring in the glow plug circuit
- Failed glow plug relay or fuse
- Corroded or loose connectors
02. Symptoms You Will Notice
- Hard starting, especially in cold weather
- Engine misfire or rough idle
- Check Engine Light illuminated
- Excessive smoke from exhaust on startup
03. Step-by-Step Diagnosis
Step 1: Use a scan tool to confirm P1393 and check for other codes.
Step 2: Visually inspect glow plug wiring and connectors for damage or corrosion.
Step 3: Test glow plug resistance with a multimeter (should be low ohms).
Step 4: Check glow plug relay and fuse operation.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive with this code, especially in cold weather, as it can cause hard starting and potential engine damage from unburned fuel.
How much does it cost to fix?▼
Repair costs typically range from $50 to $150 for parts and labor, depending on the specific cause and vehicle model.