W T E C I I I E L E C T R O N I C C O N T R O L S T R O U B L E S H O O T I N G M A N U A L
Main code 53 indicates a failed offgoing speed test. The speed test during a shift is designed to ensure neutral is
attained during shifts to neutral. This test compares engine speed to turbine speed. If neutral is selected and turbine
speed is found to be much lower than engine speed, the ECU sees this as neutral not being attained. The
transmission is commanded to Neutral with No Clutches and code 53XX is set. Additional codes could be logged
for other shifts where X indicates the range from and Y indicates the range to.
This test is not performed if neutral output is below 200 rpm or when temperatures are below a
calibrated 0°C (32°F).
Active Indicator Clearing Procedure:
Manual subcodes 78 and 99 only
Before troubleshooting, read Paragraph 56. Also, check battery and ECU input voltages.
Intermittent connections or lack of battery-direct power and ground connections may cause this and
1. Be sure the transmission is warm and the fluid level is correct. Correct transmission fluid level as
2. Using the DDR, check the engine and turbine speed sensor signals under steady conditions. If a
tachometer is available, compare the tachometer reading with the engine rpm reading on the
diagnostic tool. Check signals in neutral, at idle, high idle, and maximum no load rpm. If a signal
is erratic, check sensor wiring for opens, shorts, and shorts-to-ground (refer to code 22þXX).
Check all connections for dirt and corrosion. If wiring problems are found, repair or replace as
N3N2 or N2N3 shift
CODE 53 XX OFFGOING SPEED TEST (DURING SHIFT)