R34 Gtt Speed Sensor

[sirjb]

I am currently having two codes coming up after a while of driving being:

Code 14: Vehicle Speed Sensor

Code 34: Knock Sensor

The knock sensor error is thrown straight after the vehicle speed sensor error is thrown.

Does anyone have any ideas as to what could be causing this?

[sirjb]

Any one? I have tried swapping out the rear speed sensors with no avail.

[Jayden.K]

What conditions did the codes appear. Hard driving? Have you tried clearing and seeing if they don't come back

[sirjb]

OK. So a bit of an update: I fixed the knock sensor, it turned out to be a broken wire. The speed sensor is still an issue. The engine light comes on and then the TCS and Slip light comes on. If you turn the car off the TCS and Slip light go out when you turn it back on. When I clear it it goes away for a while, then randomly it comes back. Doesnt matter on the type of driving. Also when I plug in my laptop, the speed gauge in Nistune has no reading. The only thing I can find with the same problem is this but it talks about a de-limiter and I am not aware of my car having one. Any help would be appreciated.

[sirjb]

I have traced the problem down to the dash. The speed signal goes in from the speed sensor but doesn't send a signal back to the ecu? Any ideas why? Does anyone have a circuit diagram? Or can provide any info?

[GTSBoy]

The circuit diagram is in teh workshop manual which is available for download after a google.

This wire is sometimes cut by ruffians (at the ECU end) to kill the 180 speed cut.

[sirjb]

I am looking for a circuit diagram not an input/output wiring diagram. I have checked the output at the dash. The dash isn't sending anything out.

[GTSBoy]

Oh, well in that case the dash has a fault. There's integrated circuitry in there to do the speed signal translation (takes in a saw tooth AC voltage from the speed sensor and outputs a 0-5v square wave for the ECU). That stuff would be nigh impossible to repair unless it was a broken track on the dash circuitboard or something equally trivial.