[Mk2] [Generic] P/S not working even after replacing all parts

[monstr2]

Hi,
My car is a UKDM,REV 3,NA and the P/S system is not working even

after i have replaced the P/S ECU,driver,relay,sensor and motor and the

mechanic says there is no current flow from the speedometer gauge

onwards and that the P/S motor starts and shuts off after 10 secs.

Is the operation of the p/s motor related to the speedo meter gauge in

any way because in the chapter on diagnosis codes in the repair manual it

does not say so anywhere?

[shinny]

Step one... ask the PAS ECU what the problem is and post the code up here: http://shinny.co.uk/toyota/MR2_SW_1993_ ... agnosi.pdf

To answer your question, yes, the PAS is regulated by the speedo pulse. However if there is no speedo input, the PAS will never turn off. I don't know what "current flow" your mechanic is expecting onwards from the speedo! The signal is fed to both the PAS and engine ECUs, but both will be detecting it using high impedance circuitry so the actual current flow will be negligible.

[hmltnangel]

The speedo gauge (if its a Rev 2 onwards) will determine whether the PAS works.

If the speedo cog is stripped or the electronics inside the sensor are dead, then you will have no PAS.

This happened on mine, tried ECU, PAS ECU, Relay and nothing worked.

If there is no current coming from the Speed Sensor then it stands to reason that it is dead.

I have one for sale if needed for a Turbo.

[monstr2]

Step one... ask the PAS ECU what the problem is and post the code up here: http://shinny.co.uk/toyota/MR2_SW_1993_ ... agnosi.pdf

To answer your question, yes, the PAS is regulated by the speedo pulse. However if there is no speedo input, the PAS will never turn off. I don't know what "current flow" your mechanic is expecting onwards from the speedo! The signal is fed to both the PAS and engine ECUs, but both will be detecting it using high impedance circuitry so the actual current flow will be negligible.

Thanks for the advice shinny, ill get the car back home and get some other mechanic to look at the issue.

[monstr2]

The speedo gauge (if its a Rev 2 onwards) will determine whether the PAS works.

If the speedo cog is stripped or the electronics inside the sensor are dead, then you will have no PAS.

This happened on mine, tried ECU, PAS ECU, Relay and nothing worked.

If there is no current coming from the Speed Sensor then it stands to reason that it is dead.

I have one for sale if needed for a Turbo.

The car is a rev 3,NA and the speedo meter works fine.Which sensor are you refering to?

[shinny]

The other way to check if the speedo signal is working OK is to check the ECU error codes. If there's a problem with the speedo, the error code will be stored there

A 10s delay makes me wonder if there's a problem with the encoder ring on the steering column. From my experience when you first start the car, the PAS pump will be on for about 10-15s and then shut off. If then only comes back to life when the steering wheel is moved. If a fault has occurred in the encoder such that the PAS ECU never gets the signal that the steering wheel has moved, the pump will never come on again, but no code will be thrown by the pump either.

What you've not told us is whether the P/S warning light comes on when the pump turns off?

[monstr2]

del

[Peter Gidden]

And the result of the test for error codes as suggested earlier was???

[monstr2]

And the result of the test for error codes as suggested earlier was???

The mechanic says the test pointed to a problem in the wiring.

[monstr2]

The other way to check if the speedo signal is working OK is to check the ECU error codes. If there's a problem with the speedo, the error code will be stored there

Do you mean the engine ECU?

A 10s delay makes me wonder if there's a problem with the encoder ring on the steering column. From my experience when you first start the car, the PAS pump will be on for about 10-15s and then shut off. If then only comes back to life when the steering wheel is moved. If a fault has occurred in the encoder such that the PAS ECU never gets the signal that the steering wheel has moved, the pump will never come on again, but no code will be thrown by the pump either.

Would the encoder ring mean the steering sensor?
If so i've replaced this too.



What you've not told us is whether the P/S warning light comes on when the pump turns off?

I've replaced the steering sensor.

Yes the P/S warning light does come on when the pump turns off.

[shinny]

And the result of the test for error codes as suggested earlier was???

The mechanic says the test pointed to a problem in the wiring.

That's nice... did he tell you which code was it?

[Peter Gidden]

That's nice... did he tell you which code was it?

[monstr2]

And the result of the test for error codes as suggested earlier was???

The mechanic says the test pointed to a problem in the wiring.

That's nice... did he tell you which code was it?

I had swapped the rack assy & housing along with the p/s motor

between my JDM,REV 1 tubby and REV. 3 NA after the p/s in the newly

purchased tubby was found to be harder to turn.

Do you think i should swap the parts back before i proceed any further?

[Peter Gidden]

The mechanic says the test pointed to a problem in the wiring.

That's nice... did he tell you which code was it?

Haha its because the mechanics located 20 miles from where i live that i

found it difficult to manage things.

[Driftlimits Performance]

Steering angle sensor

[monstr2]

Steering angle sensor

I've already replaced this part.

[killerferret666]

not that I can offer much direct help other then to say if you need any other part to replace I have them all lying around somewhere, ECU, Pump, Rack etc... As i decided to bin the PAS.

good luck!