GTC505m Engine Ignition Analyzer

Finding dead or malfunctioning coils and plugs can be hard work. The GTC505 makes ignition troubleshooting quick, easy, and painless. It’ll help you, and the people depending on you, get moving again!

The GTC505 is the product of 20 years of work (by GTC) on ignition diagnostics. This tool will tell you exactly what’s going on with any spark ignition system as soon as you put its sensor by your coil (or spark plug wire). Swapping coils and other components in and out until you figure out what’s wrong is slow, tedious, and wasteful. The GTC505 will take the guesswork out, so you can be confident that the problem will be solved on your first try.


Quick Links


Who it’s For:

  • Marine outboard mechanics
  • Gasoline inboard mechanics
  • Small engine repair shops doing fault diagnostics
  • Motorcycle technicians doing diagnostics or aftermarket modification
  • Automotive technicians looking for a GTC505 with all the extras

What it Does:

Quickly and easily detects engine RPM and spark parameters. Useful for checking for ignition system faults and misfires, or for tuning and aftermarket modifications.

How it Works:

  1. Connect the appropriate sensor
  2. Turn the unit on
  3. Position the sensor near the ignition module or wire
  4. Check the engine RPM, spark peak voltage, burn time, and dwell angle/ramp time. The digital view gives you a quick look at the average, and the chart view will show you any misfires.

Warranty & Support:

Covered by our standard 1-year warranty, and supported for much longer. Replacement parts and accessories are generally available for 10+ years.






Analyzer Specifications


  TA100 TA500 GTC505
Measures Engine RPM
Measures Peak Spark Voltage
Measures Spark Burn Time  
Measures Dwell Angle    
Measures Ramp Time    


Pickup Specifications


  TA100 sensor TA500 sensor GTC505 COP sensor GTC505 SPW sensor
Capacitive Sensor
Inductive Sensor      
Works on Capacitive Discharge Systems  
Works on Distributor Systems  
Works on Magneto System  
Works on Coil-On-Plug Systems    


How-To Videos

GTC505 - How to connect the flex-arm and sensors

GTC505 Misfire Detection



What is the difference between the GTC505, the GTC505m, and the GTC014?

The GTC505 is an engine ignition analyzer. The most basic kit it comes in: with a flexible probe, extension cable, cop sensor, spw sensor, USB micro cable and AC charger adapter, user’s manual, 1 year warranty, and hard padded carrying case.

The GTC505m is an upgraded version of the GTC505 kit – it comes with everything in the GTC505 kit, but with the GTC014 accessory, and a larger hard padded carrying case to accommodate the extra accessory.

The GTC014 can be purchased separately (here), or together with the analyzer in the GCT505m kit.

  GTC014 GTC505 GTC505m
Engine Ignition Analyzer  
Flexible Probe  
Coil on plug (COP) active sensor  
Spark plug wire (SPW) shielded capacitive sensor  
Clip-on spark plug wire capacitive sensor  
Extension cable with BNC and sensor connector  
USB micro cable and AC charger adapter  
Protective rubber holster  
Hard padded case for carrying and storage  
User’s manual  
1 year parts and labor warranty  



  Download Brochure (English)
  Download Manual (English)

Kit Manifest

  • GTC505 engine ignition analyzer (core unit)
  • flex-arm
  • COP pickup
  • SPW pickup
  • Clip-on SPW pickup
  • 2m (extended) cable
  • USB-A to micro-B USB cable 0.9m (3′) long
  • AC to USB power adapter (charger)
  • hard-shell, padded storage and carrying case
  • user’s manual


Parts & Accessories



Proposition 65 Warning ⚠

This product can expose you to chemicals including Styrene, which is known to the State of California to cause cancer, and Bisphenol A (BPA), which is known to the State of California to cause birth defects or other reproductive harm. For more information go to: