Trouble Code 20 (Speed Signal n-ab)

SPEED SIGNAL n-am
Explanation
This defect code is stored when the control unit receives no output speed signal at an engine speed above approx. 3000 rpm in a drive range (R, D, 3, 2, 1).

Effect of Defect
Mechanical emergency program.

Possible Cause
Wire from Electronic Transmission Control (EGS) control unit Pin 14 and 20 to speed sensor, speed sensor, torque converter or clutches defective.

Troubleshooting
- Jack up vehicle
- Start engine
- Engage drive range D
- Perform status monitoring - Speed signal n-ab

NOTE: The EGS speed signal n-ab is not identical to the speed-A signal)

1. If a speed signal is indicated and vehicle has poor power transmission after new start the Torque converter or clutches are defective (automatic transmission fluid ATF burnt).

2. Speed signal n-ab equal to 0 and vehicle has good power transmission after new start the speed sensor or wires to speed sensor are defective.