🔢
Coil G is typically cylinder 7. A circuit code (vs. a misfire code) means the PCM sees an electrical fault - open coil winding, broken trigger wire, or shorted control circuit. Swap with another cylinder coil to confirm before buying parts. See top-rated scanners on Amazon ↗
🗺️ Where Is the Problem?
Blueprint view - P0357 affects engine sensors and management circuits
These are statistical causes across ALL vehicles - your exact car may rank differently
For example, on a Honda 4-cyl the downstream O2 sensor causes P0357 64% of the time, but on a GM 5.3L V8 the catalytic converter is the cause 71% of the time. Get a probability ranking built specifically for your year, make, model, and mileage.
🔎 Get the ranking for my exact car - $5.99 →
🎯 Top Causes & Probability
55%
#1 - Most Likely
Failed Ignition Coil (Cylinder 7)
The coil's primary or secondary winding has gone open or shorted internally. Cracked boots are also common, allowing spark to leak to ground. Swap the coil to a known-good cylinder - if the fault follows the coil, it's confirmed.
🔨 Part
$20–$130
👨🔧 Labor
$30–$120
⚡ DIY Difficulty
Easy
30%
#2 - Check First
Wiring or Connector Fault
The coil control wire (from the PCM) has chafed or the connector pins are corroded. Inspect the trigger pin for green corrosion and verify continuity from connector to PCM.
🔨 Part
$10–$60
👨🔧 Labor
$50–$140
⚡ DIY Difficulty
Medium
10%
#3 - Less Common
PCM Driver Failure
The PCM's internal coil driver transistor has failed for that channel. Confirmed by swapping the coil to a known-good cylinder and seeing the fault stay on cylinder 7. PCM replacement or repair is required.
🔨 Part
$300–$900
👨🔧 Labor
$100–$250
⚡ DIY Difficulty
Hard
🚗 Most Affected Vehicles
🚫 Is It Safe to Drive?
No - an open coil circuit means cylinder 7 isn't firing, dumping raw fuel into the cat. Continued driving will damage the catalytic converter ($800+ to replace). Repair right away.
🔧 Step-by-Step Diagnosis
- Swap Coil 7 with a Neighbor - Move the coil from cylinder 7 to another cylinder and clear codes. If the new cylinder now sets a coil circuit fault, the coil is confirmed bad.
- Test the Trigger Wire - Backprobe the coil control wire while cranking. You should see brief 12V pulses. No pulses = wiring or PCM driver issue.
📍 Find a Trusted Shop Near You
Please enter a valid 5-digit ZIP code.
Tips for Choosing a Shop
- Ask if they charge a diagnostic fee and whether it applies toward the repair
- Request a written estimate before approving any work
- Ask specifically about the part brand - OEM vs. aftermarket matters for this code
- Check Google reviews for recent mentions of the specific repair you need