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Build a simple 944 Turbo Blink Code Tester

Building a blink code tester for under $4.00.

Radio Shack has several LEDs that will work for this homemade tester. You will need terminals that can be crimped or soldered onto the wires enabling you to plug into your test terminals. These Butt Terminals work well but are not insulated. You can solder the terminals onto the wires and end up with something that looks like this.

Green LED ~ Catalog #: 276-271 $2.19
Crimp-On Butt Connectors ~ Catalog #: 64-3036 $1.69 (Use the small connectors in the package)

Plug the new code testers positive (red) and negative (black) into the terminals pictured below.

These codes are really just from the KLR. Run the codes right after a test drive with the engine still running, or running the engine above 1500 RPM will also store the codes. As soon as you turn off the car, the stored code is erased. Each single blink code is actually a two digit code, meaning, count the first # of blinks, a short pause, and then the second # of blinks.

Listed below are the codes | possible repair

1-2 voltage under 10.2 | check alternator, battery, regulator, relays or wiring
2-1 knock sensor | Engine damage, tappets rattle, faulty valve, rod bearing, engine knocks.
2-2 knock sensor | Sensor Installation, plug connection at sensor
2-3 KLR defective | Replace KLR
3-1 boost pressure low or zero | Bad wastegate, turbo or intercooler leaks.
3-2 boost pressure to high | Bad Wastegate, cycling valve, wastegate hose off.
3-3 pressure sensor in KLR defective | Replace KLR
4-1 throttle position sensor or wires | Power wire to TPS, ground contact or connection dirty.
4-2 throttle position sensor or wires | TPS bad, but check wires first.

Keep in mind, you could have low boost but not low enough to set off code 3-1. Another important note, manual states if you get code 4-1 & code 3-3 together, ignore 3-3. Lastly, you might want to verify all this by unplugging the TPS, drive around the block or running about 1500rpm, and see if it blinks code 4-1.