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hi just got the awesome udt999 tool delivered and hooked it up for a quick look see to see if I can finally get to the bottom of my feeling that car just not running right
so far I've turned up two error codes on the ezk
Hall effect and load signal
Hall effect prob easy enough to fix but I'm not sure about load signal diagnosis ?
Anyone had any luck fixing these ? Prob goes long way to explaining why car just doesn't feel right!
cheers
j
A Hall sensor fault is easy, it'll pull 6 degrees of timing and the car will feel weak. Likely the connector, Roger sells a replacement connector kit, rather than having to buy the whole new Hall sensor.
The manual for the UDT999 has the following bit on the load signal the EZK 'sees':
LOAD
This tells the EZK how much load the engine has to cope with. It is a signal derived from the LH controller and expressed in nanoseconds. The signal is derived from the MAF seA lonsor data and Rpm. The load signal varies with the load on the engine. A value of 70 μSec to 80 uSec at idle speed is normal. The load will increase when you blip the gas or put the engine in gear, moving off. The actual value is shown in the box next to the button. A blue bar-display to the right helps putting the value into perspective of the allowed range.
The load signal sent to the EZK is related to the fuel injector pulse duration measured (or generated?) by the LH, but I don't know why you'd get a load signal error- is your gas mileage reporting correctly? (Or do you have an '87-88?)
When the Hall trigger or either knock sensor fails the timing is retarded by 6 degrees across the board as a safety measure. Changing the unit is not that difficult but can be tricky if doing it with the cam wheels in situ if the mounting screws are difficult due to corrosion.
Not sure what the term "load signal" refers to in the context of the device you are using. I would expect such terminology to refer to the output signal from the MAF but if that fails the car is going nowhere or so I would think. I suppose the other possibility is the full throttle switch contact- easy to test if that is working [or not] but how the tool would diagnose such is beyond me. This is a common failure and if it is not working then the mapping stays on the cruise maps rather than the full throttle maps.
The load signal goes from LH fuel injection module connector pin 25 to EZK connector pin 9.
The failure may be that the EZK is not reading the load signal. Check the connector pins at the LH and EZK for corrosion and test the circuit for connectivity.
An internal failure of the LH fuel injection module would be the cause of no load signal generated.
An internal failure of the EZK spark module would be the cause of no load signal received.
The manual for the UDT999 has the following bit on the load signal the EZK 'sees':
As an aside, the Theo manual is a font of knowledge for information on how the various 928 brains function. (It was a great help to me in understanding the assembly language code in the EZK and LH.)
Cheers for quick responses guys I'll try to get a better look at it this week
sorry meant to say car is a 1990 s4
I've attached pic of ezk error codes these match the factory wsm codes according to udt documentation
ive recently had both lh and ezk checked by John so hopefully not a fault with either for the load signal maybe just a bad connection I'll buzz it out and check hall sensor connector and wiring
cheers
If the EZ understands that the load signal is faulty does it default to the lowest advance setting in each rpm array given it must assume something under a default condition?
10-15-2017, 12:01 PM
Hall sensor and load signal errors
