BASIC FAULT FINDING GUIDE FOR COSSIE ECUS

NOTES:
Some of these results can be affected by an alarm system or imobilizer.
I have assumed the car has a 2.5 bar/3.0 bar map sensor and is 4x4 L8/P8.
If SECS monitor is fitted, unplug it !
(A faulty monitor or incorrectly fitted can cause engine not to run)

1) Ensure ignition is OFF.

2) Remove rear of ecu plug cover and insert plug back into ecu.

3) Turn ignition back on (do not start engine)

4) MAIN POWER CHECK: Check for DC voltage of at least 11.5 volts between ecu pins 19 and 20.

5) REFERENCE CHECK: Check for DC voltage of around 4.8 to 5.2 volts between pins 11 and 30.

6) MAP SENSOR CHECK: Check for DC voltage of around 1.8 to 2.5 volts between pins 11 and 15.

7) THROTTLE CLOSED: Check for DC voltage less than 0.5 volts between pins 11 and 17.

8) THROTTLE FULLY OPEN: Check for DC voltage greater than 4.5 volts between pins 11 and 17.

9) Turn ignition off, unlpug ecu, turn ignition back on (dont forget imobilizer if fitted)

10) CRANK SENSOR: Check resistance between pins 3 and 4 between 300 and 1200 ohms.

11) CRANK SENSOR: Check AC voltage on pins 3 and 4 while cranking engine.
Should be at least 2 volts.

11) PHASE SENSOR: Check resistance between pins 5 and 23 between 300 and 1200 ohms.

12) PHASE SENSOR: Check AC voltage on pins 5 and 23 while cranking engine.
Should be at least 1.5 - 2 volts.

12) INJECTOR: Check resistance from pins 18 to 20 should be 2 to 5 ohms.

13) INJECTOR: Check resistance from pins 35 to 20 should be 2 to 5 ohms.

14) INJECTOR: Check resistance from pins 33 to 20 should be 2 to 5 ohms.

15) INJECTOR: Check resistance from pins 32 to 20 should be 2 to 5 ohms.

16) IGNITION TRIGGER: Read voltage between pins 24 and 25, should be at least 4.5 volts.

17) IGNITION TEST: BEWARE DANGEROUS VOLTAGES ON PLUG/COIL LEADS.
Quickly link pins 24 and 25 on and off this will FIRE the ignition coil.
Rotate dizzi by moving car in gear to point rotor arm at one plug lead
and remove spark plug (earthing it on chassis or engine) to see spark.
(Dont touch it or you will fry)
Try for each plug in turn.
Or remove king lead at dizzi and place end within 1 centimetre of earth
to see a big spark.

18) Place a temporary wire link from pin 1 to pin 10. (energises ecu power relay)
You should hear a click.

19) Quickly link pins 19 to 28 to test fuel pump runs.

20) COOLANT TEMP: Check resistance pins 29 and 11 for 800 ohms to 5000 ohms (depends on temp)

21) CHARGE TEMP: Check resistance pins 31 and 11 for 800 ohms to 5000 ohms (depends on temp)


These are only basic tests but will find 99% of faults icon_mrgreen.gif