Throttle Valve Opening Signal Circuit Check

Reference:

Throttle valve opening signal is pulse.

Oscilloscope waveform of throttle valve operating signal as shown in the figure.

Connect oscilloscope between terminals "E61-4" and "C51-3-6" of connected ECM connector.

Fig 1: Oscilloscope Waveform Of Throttle Valve Operating Signal

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Step	Action	YES	NO
1	DTC check  Check DTC referring to DTC CHECK . Is there a DTC related to throttle position sensor?	Go to applicable DTC flow.	Go to Step 2.
2	Throttle valve opening signal circuit check  Turn ignition switch ON. Check voltage between terminal "E61-4" of ECM connector connected and ground. Courtesy of SUZUKI OF AMERICA CORP. Does voltage vary linearly according to throttle opening?	Throttle valve opening signal circuit is OK.	Go to Step 3.
3	Supply voltage check  Disconnect connector from ECM with ignition switch OFF. Check for proper connection to ECM at terminal "E61-4". If OK, connect "BLU" wire terminal of main relay to ground with service wire. Turn ignition switch ON. Check voltage between terminal "E61-4" of ECM connector and ground. Is it 10 - 14 V?	Check TP sensor and circuits referring to DTC P0121: THROTTLE POSITION SENSOR CIRCUIT PERFORMANCE . If OK, substitute a known-good ECM and recheck.	Check "GRY" wire for open and short. If OK, proceed to cruise control module power and ground circuits check.