Terminals Of ECM

CHECK ECM

Fig 1: Checking ECM

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Measure the voltage and resistance of the wire harness side connectors.

Standard:

ECM TERMINALS SPECIFIED CONDITION

Symbols (Terminal No.)	Wiring Color	Terminal Description	Condition	Specified Condition
STP (E5-4) - E1 (E3-7)	G-R - BR	Stop lamp switch input signal	Brake pedal released (Stop lamp switch OFF)	Below 1 V
STP (E5-4) - E1 (E3-7)	G-R - BR	Stop lamp switch input signal	Brake pedal depressed (Stop lamp switch ON)	7.5 to 14 V
CCS (E5-31) - E1 (E3-7)	R- BR	Cruise control main switch output signal	Ignition switch ON	10 to 16 V
CCS (E5-31) - E1 (E3-7)	R - BR	Cruise control main switch output signal	Ignition switch ON, CANCEL switch ON	6.9 to 9.8 V
CCS (E5-31) - E1 (E3-7)	R - BR	Cruise control main switch output signal	Ignition switch ON, SET/COAST switch ON	4.7 to 6.9 V
CCS (E5-31) - E1 (E3-7)	R- BR	Cruise control main switch output signal	Ignition switch ON, RES/ACC switch ON	2.4 to 3.8 V
CCS (E5-31) - E1 (E3-7)	R - BR	Cruise control main switch output signal	Ignition switch ON, Main switch ON	Below 1 V
ST1- (E6-8) - E1 (E3-7)	Y-G - BR	Cruise cancel input signal	Ignition switch ON, Brake pedal depressed (Stop lamp switch ON)	Below 1 V
ST1- (E6-8) - E1 (E3-7)	Y-G - BR	Cruise cancel input signal	Ignition switch ON, Brake pedal released (Stop lamp switch OFF)	7.5 to 14 V
E1 (E3-7) - Body ground	BR - Body ground	Ground	Always	Below 1 V
SP2- (E3-22) - SP2+ (E3-23)	R - G	Vehicle speed is actual speed	Vehicle is driving	Pulse generation (see WAVEFORM 1 (REFERENCE) )

If the result is not as specified, the ECM may have a malfunction.

Inspect using an oscilloscope.

Waveform 1 (Reference):

WAVEFORM 1 (REFERENCE)

Symbols (Terminal No.)	SP2- (E3-22) - SP2+ (E3-23)
Tool Setting	2V/DIV., 20 msec./DIV.
Vehicle Speed	20 km/h (12 mph)

HINT:

The wavelength becomes shorter as vehicle speed increases.

Fig 2: Identifying Waveform 1