Code 33

[Brucey 95wrx]

I have a code 33 showing when I plug the 2 black plugs in under dash and judering after 4500 revs 

its a 1995 import wrx jdm 

any help would be great 

[Guest]

Does this car have OBD1 or OBD2 version? code 33 doesnt really mean much in my experience. Usually a letter before hand  in a fault code. if you can give me more info i can point you in the right direction 😃

 

[WideSam]

Code 33 is a speed sensor issue... Has your speedo been changed to read in mph? 

[Brucey 95wrx]

Obd1 and yes it reads in mph but so so many cables have been messed with it’s a pain I don’t know where to start I have replaced cam shaft sensor but when I try to give it the beans the engine light comes on and the Rev counter goes mental up down reading zero even tho I’m still moving but engine doesn’t die 

[Brucey 95wrx]

And just coughs and splutters at 4500 in 5  trying to go but then backing off 

it warms up fine and boosts well for 3-5 mins then the light comes on and I keep getting 33 

[WideSam]

Once a speed sensor fault has been detected it’ll put the car into limp mode. It could be one of 2 things: 

1) Your speed sensor is knackered

2) The gubbins that converts the speedo from kmph to mph is playing up. This seems more likely because it involves splicing things into wires behind the clocks. 

Apologies for the vagueness, electrics really isn’t my forte 😂

[Brucey 95wrx]

Any idea what to look for behind the clocks as my clocks seem to have the middle strip in between rev and speed like the autos but mine is manual so I don’t know if they just changed the clocks? 

Where is the speed sensor? 

[Brucey 95wrx]

That’s what my clock looks like 

[Brucey 95wrx]

But my dials are white and say mph 

[savage bulldogs]

The strip down the center of the clocks is either for auto or DCCD boxes , afaik. 

Think being a v2 it would have the mechanical speedo drive ?

If so are your clocks showing the right speed and working smoothly?

I had a no ECU speed reading on my v1sti but it's running apexi f.c ,so didn't matter until I tried to get my avcr gear judge function working. 

It took me a while to find out why but it was because someone had removed this screw on the back of the clocks .

Once I refitted the screw the speed reading returned to the apexi ECU. 

[Brucey 95wrx]

Yeah mine is mechanical I have taken all of that apart cleaned with electrical contact cleaner hopefully it will work being mechanical will I have a sensor on the gearbox or is just the cable that spins? 

[savage bulldogs]

If yours has a speedo cable (mechanical speedo drive) I think, the mechanical to electrical speed sensor converter is in the back of the clocks . As there is no other wires attached to the box in that area and v3 onwards have a electrical speedo drive,(just wires from the speedo drive to clocks  , no cable)

I assume someone removed the screw in my clocks ,maybe to "de limit" or fit something else aftermarket,  that needed a speed reading .

Does the speedo read ok ? 

If so it's probably more likely to be a fault /issue where the cable plugs into the clocks or the printed circuit near it 

[Brucey 95wrx]

Yeah the speedo works fine nice smooth motion I’ve only just got it back on the road after my cam belt slipped 2 teeth and now yet another problem after 10 mins of driving 😂 

[savage bulldogs]

A visual check at the back of the clocks for loose connectors and damage to the circuit board ,would be where I'd start .

Also a ECU reset might help , as you might have resolved the problem by cleaning the cable and it's just flashing up the old code .

If that doesn't work I can dig out some info on which ECU pins to check , if you want ?

[Brucey 95wrx]

Yeah that would be great if you could buddy thank you very much 👍🏽 

[savage bulldogs]

Had a squint at the service manual and it mentions a "speed sensor (2)"   I'm not sure if this means there's 2 types (cable and electrical) or that's there's 2 sensors tbh .

It shows it near the brake servo (could be either side of the bulkhead ) theres a pic with a number 7 pointing at the part below. 

The sensor itself needs a oscilloscope to check while running with all 4 wheel off the ground but theres a ECU pin plug list and pic . This is taked from looking at the wires with the ECU harness plugs plugged into the ECU  😉.

And a pin voltage /resistance check for the ECU/speed sensor harness. Pics will probably post in the wrong order , so hope you can make sense of it lol.

Best of luck with it , chap 👍

 

[savage bulldogs]