Diagnostic for a friend 

22nd October 2003

A diagnosis procedure was performed to one of friend's AE92 with full transplant of AE101 20vAFM including dashboard and air-cond systems.

Once the Scantool is plugged in, it registered two error codes. Namely 24 and 31. Which is Intake Air Temperature Sensor and Vacuum Sensor. Since AFM does not use vacuum then it is highly suspected to the AFM's Flap signal bad. If so then both items are related to the AFM.

There is a high chance that the installer start the car without installing the AFM, hence the ECU registered bad / missing / short AFM's Flap and Temp Sensor.

So the battery is removed to erase error log and then put back and start the car and drive for two rounds. Came back to check again, no more error code.

After that was cleared. It is time to check the injector's pulse width, which was OK, everything else is OK.

Now Timing Light Gun on crank to check timing. Way -off at 15 degrees. So retard back to 10 degrees.

Then set TPS to best sensitivity. Difficult to get. Then I adjusted the AFM's by-pass valve full downwards to give it more umph, where the Flap may open more easily. Woh_la the TPS's Idle register quick response.

Test car. The car immediately felt more easy / willing - especially at partial clutch release for extremely slow moving times like reverse out of a car park. Previously the clutch release and accelerator is difficult to match and the car plunges at times. Now it is nice and smooth and very predictable.

Acceleration did not increase, but torque may be felt more firmer sticking to the ground. Hmmmm, you'll have to take my word for it. Hahahahahaaha.


So, is this called "Tuning" - by my definition - surely not.


I hope the readers will read everything from Kevin Sullivan's Autoshop101 Technical Articles and all the questions will be answered :)


  1. Diagnosis System
  2. Diagnostic by DCN Pro
  3. Diagnostic for a friend
  4. Different Diagnosis
  5. Results 1
  6. Results 2
  7. Results 3
  8. Results 4
  9. References



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