EG–524 ENGINE – 2JZ–GTE ENGINE TROUBLESHOOTING DTC 16 A T Control Signal Malfunction CIRCUIT DESCRIPTION The signal from the A/T CPU retards the ignition timing of the engine during A/T gear shifting, thus momentarily reducing torque output of the engine for smooth clutch operation inside the transmission and reduced shift shock. DTC No. | Diagnostic Trouble Code Detecting Condition | Trouble Area 16 | Fault in communications between the engine CPU and A/T CPU in the ECM | • ECM If the ECM detects the diagnostic trouble code "16" in memory, it prohibits the torque control of the A/T which performs smooth gear shifting. INSPECTION PROCEDURE 1 Are there any other codes (besides Code 16) being output? NO YES Go to relevant diagnostic trouble code chart. Replace engine control module.