BR–150 BRAKE SYSTEM – TRACTION CONTROL SYSTEM (TRAC) INSPECTION PROCEDURE HINT: The main throttle position sensor signal is transmitted to the TRAC ECU from ECM, so if an error occurs at the engine side, the TRAC ECU also detects it. If diagnostic trouble code No.41 is being output for the engine troubleshoot the engine first. 1 Is diagnostic trouble code output for the engine? Do diagnostic trouble code check on page EG–491. NO YES Repair circuit indicated by the code output. 2 Check voltage between terminal IDL1 of TRAC ECU and body ground. P 1. Remove TRAC ECU with connectors still connected. 2. Disconnect the vacuum hose from the throttle opener, and apply the vacuum to the throttle opener. 3. Turn ignition switch ON. C Measure voltage between terminal IDL1 of TRAC ECU and body ground, when the main throttle valve is fully closed and fully open. OK Main throttle valve position | Voltage Fully closed | Below 1.0 V Fully open | 10 – 14 V ON IDL1 R06991 BE9653 R06992 NG OK Go to step 6 .