Test TC-15A - Speed Control Solenoid Circuits Or Speed Control Power Relay Circuits

NOTE: For appropriate wiring diagram, see WIRING DIAGRAMS .

Using scan tool, read, record and clear DTCs. Start engine. Using scan tool, monitor Speed Control (S/C) ON/OFF SWITCH STATE while switching speed control on and off. If scan tool display switches ON then OFF, perform TEST TC-15B . If scan tool display does not switch ON then OFF, go to next step.

Disconnect speed control switch connector. Using an external ohmmeter, check resistance across specified speed control switch terminals. See Figure . If resistance is not as specified, replace speed control switch and perform TEST SC-VER . Refer to SPEED CONTROL SWITCH RESISTANCE SPECIFICATIONS . If resistance is as specified, go to next step.

SPEED CONTROL SWITCH RESISTANCE SPECIFICATIONS

Switch Position	Check Between Pin Nos.	Ohms
Off	1 & 2	798-814
Off	2 & 3	Open
On	2 & 3	900-918
Resume/Accel	2 & 3	15,246-15,554
Set/Coast	2 & 3	6584-6716

NOTE: DO NOT depress brake pedal during following step.

With speed control switch on, disconnect speed control servo 4-pin connector. Inspect connector and terminals for damage. Repair connector and terminals as necessary and perform TEST SC-VER . If connector and terminals are okay, go to next step.
Using a scan tool, actuate the speed control vent solenoid. Using scan tool in voltmeter mode, check voltage on speed control servo 4-pin connector, switched speed control power supply circuit (Dark Blue/Red wire). See Figure . If voltage reads more than 10 volts, perform TEST TC-15B . If voltage reads 10 volts or less, perform TEST TC-15C .