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 occurs in diesel engines where glow plugs are used to aid cold starts. The low input suggests a short to ground, open circuit, or a faulty glow plug, relay, or wiring. This can cause hard starting, especially in cold weather, and may trigger the check engine light.
1. Symptoms You Will Notice
- Hard starting, especially in cold weather
- Check engine light illuminated
- Rough idle or misfire after cold start
- Excessive smoke from exhaust during startup
2. Most Common Causes
- Faulty glow plug in bank #2
- Open or shorted glow plug wiring or connector
- Failed glow plug relay or fuse
- Corrosion or damage in the glow plug harness
3. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect glow plug wiring and connectors on bank #2 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 for proper operation.
Step 5: Perform a glow plug output test using a scan tool or test light.
4. 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 repeated cranking.
How much does it cost to fix?▼
The cost to fix P1393 typically ranges from $50 to $150 for parts and labor, depending on whether it's a single glow plug or wiring issue.
5. Commonly Affected Makes
This is a manufacturer-specific code. The exact manufacturer is not confirmed in our current database.