You don't need anything fancy for this, your GT, its key and a short length of wire - thats it!

Procedure:
1: turn the ignition key to MAR, without starting the engine

2: find the 3 pin diagnostics port located at rear of engine bay under the plastic cover (see pic).
699IMAG0007-med.jpg

3: Remove the cover (if its still there) and find the pin which has a blue/white wire. Stick one end of your little length of wire in the pin with the blue/white wire and stick the other end to earth for 4 seconds - the inlet manifold is a good bet for the earth as its right there next to the diagnostics port. This will start the readout process:

3- the ECU light should light for a long flash (~2 secs) followed by the blink code of the first fault (4 digits indicated by blinks separated by ~0.5sec then a longer pause ~1.0sec between digits then ~2 secs before the code is repeated)

4- I'm not 100% sure about this (only verified for GT2 & GT3 ECUs) earthing the blue/white lead again should cause the next code to be repeated in a loop. When all fault codes have been read out, the light will flash 1111, 4444 or, possibly 3333, this indicates end of codes. If you get either of them at the start then there is no stored codes.

5- turn ignition off, your done. Refer below for list of codes.


LIST OF CODES
1111 - No errors logged in the ECU, no malfunctions, or end-of-codes (long flashes GT2)

Out of Range Fault codes:
1211 - Battery voltage anomaly - voltage < 10 volts or > 16 volts
1214 - Coolant temperature sensor (CTS) - temp. either > 140°C or < -35°C
1216 - Throttle potentiometer sensor (TPS) - short or open circuit
1221 - Air flow meter (AFM) sensor - short or open circuit
1222 - Lamba probe - over or underfueling > 10 secs
1223 - Inner circuit lambda probe - over or underfueling / ECU
1224 - Lambda probe - lambda voltage < 0,09 V or > 1,1 V
1225 - Inlet air temp (IAT) sensor - > 140°C or < -35°C
1226 - Ignition module (coil pack)
1233 - Idle control valve (ICV) - final stage
1235 - Air conditioning compressor - IN signal
1236 - Air conditioning compressor - OUT signal
1244 - Carbon canister solenoid valve - short or open circuit / ECU
1251 - ECU defective - (RAM or EPROM)
1252 - Tachometer sensor signal
1255 - Phase sensor signal
1256 - RPM/crank sensor - N.B. for some ECUs, this may occur if the engine isn't running and may be ignored - so ignore if you have no running issue.
1257 - Top Dead Centre (TDC, RPM/crank) sensor signal - (Check the Air Gap before replacing)
1261 - Electroinjector cylinder 1 - short or open circuit
1262 - Electroinjector cylinder 2 - short or open circuit
1263 - Electroinjector cylinder 3 - short or open circuit
1264 - Electroinjector cylinder 4 - short or open circuit
1265 - Injection warning light malfunction - check the bulb

1311 - Electroinjector cylinder 1
1312 - Electroinjector cylinder 2
1313 - Electroinjector cylinder 3
1314 - Electroinjector cylinder 4


Actuator test codes (these are not fault codes)
You have entered the actuator tests.
Probably, you have earthed the blue-white cable before turning the ignition key to MAR.
1412 - Idle control valve (ICV) actuator
1413 - Carbon canister solenoid valve
1421 - Injector 1
1422 - Injector 2
1423 - Injector 3
1424 - Injector 4


Sensor Error Fault codes:
2111 - Knock sensor malfunction
2114 - Throttle potentiometer/postion sensor (TPS) - false contacts or bugs
2116 - Invalid test - repeat the operation
2121 - unknown - check for inlet manifold and ICV gasket leaks and vac. pipes
2124 - Phase sensor
2125 - Barometric pressure sensor

2131 - Either tachometer or RPM/crank sensor malfunction (GT2)? Possibly temperature related?
2133 - Not defined
2134 - Over-boost electrovalve (Pierburg valve/PBV) malfunction - short or open circuit
2135 - Manifold absolute pressure (MAP) sensor (internal to ECU)

3211 - Manifold absolute pressure (MAP) sensor malfunction (internal to ECU)
3232 - unknown - reported symptom, pressure in coolant system, possible oil pressure problem

3333 - Possibly the same as 4444 below (unconfirmed)

4444 - No errors logged in the ECU, no malfunctions, or end-of-codes (GT3)


Fault codes are kept in memory for some engine start-ups, then they are gradually removed. To reset the memory just unplug the ECU, or disconnect the battery for a few minutes.