Is it possible that something is causing the controlers to fail when plugged in?


The Over Voltage Protection relay should protect the controllers. You should always disconnect the battery and discharge any static electricity by grounding yourself before disconnecting/connecting any controller.

I should have ask this question before, did the transmission ever shift into 5th gear. If the transmission fluid and pan are clean, no internal problem; then I would change the control valve for 5th gear (Y3/1y3) and the throttle valve switch (S29/4) even with no code these sensors can fail mechanically. The HGS did have an Y3/1Y3 code



The TCM / HGS receives the following electrical signals

Voltage supply, over voltage protection relay powers the TCM (HGS)
Engine speed; EZL / AKR control unit, TN signal
Load input: EZL/ AKR control unit. Manifold vacuum and DI control module
Throttle position: Throttle position switch: S29/4
Vehicle speed; Out put shaft on Trans/ speedometer. Digital and mechanical Speedo/ wheel sensor.
D contact switch: Shift lever in “D” position
Control valve: Valve body, pulse modulated



Email me or post your fax number and I will send you the diagnostic pin chart to diagnose the complete systems, plus fault codes for the MAS, EZL/AKR and the HGS.


If you have any question email a contact number and I will call you back

mastertech@mastertechtrans.com shop

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