samcowrx

I took my my94 wrx wagon to my local scoob dealer to plug into there tek 1 diagnostics machine today, (dont ask why long story) because of small misfire and check engine light coming on now and then, the managed to get the tester to work with the ignition on but not the engine started but when they tried to test with the engine running they couldnt "get into the system", it seemed like the ecu was blocking it or something so they could not get any readings at all, anyone know why this might be?, alarm immobiliser, scoobyecu chip etc? thanks

Jolly Green Monster

iTrader: (4)

no need for diagnostic machine, you can do it yourself..

ECU Error codes

Turn OFF the ignition

Connect Error code Connectors :
2 black connectors under dash, connect black to black, they are by your left knee when sat in the drivers seat and often taped back to the loom if they haven't been used before.

Turn ON ignition but don't start the engine

An Error Code is indicated by a flashing check engine light
of varying length of flash,
a flash of around once a second is the okay code and indicates all is well.

If an error code is detected Check the ECU Code

If there is a fault Check the Appropriate Sensor

Error Codes
An Error code is defined as a slow flash followed by fast flash
i.e 2 slow and 3 fast = 23 Mass Airflow sensor.
A continuous on/off at the same speed is no fault found.

Code Fault
11 Crankshaft position sensor

12 Starter switch

13 Camshaft position sensor

21 Engine coolant temperature sensor

22 Knock sensor

23 Mass air flow sensor

24 Idle air control solenoid

31 Throttle position sensor

32 Oxygen sensor

33 Vehicle speed sensor 2

35 Purge control solenoid valve

42 Idle switch

44 Wastegate control solenoid valve

45 Pressure sensor / Pressure exchange solenoid valve

51 Neutral position switch

Simon

samcowrx

have done that but it gives different codes to diag machine, that is why its a long story, i would not normally take it to dealer, but i have a proper misfire problem, which is really costing me money and time just need to get to the bottom of it.

Jolly Green Monster

iTrader: (4)

have you done a reset and seen which codes come up?

misfire can often be put down to coil packs on that year.. although not usually accompanied with a CEL unless really really bad.. do you know if they have been replaced?
Other reasons could be crank or cam sensor.. or something causing a fuelling issue.. like maf or pipework leak or coolant temp sensor.

If you have a large number of error codes then check the engine grounds and add an extra one.

Simon