NTC-1B: Checking Speed Control Operation
NOTE:
Perform NTC-1A: CHECKING SPEED CONTROL OPERATION
before proceeding.
- While observing scan tool, place transmission in Drive. If scan tool does not display P/N switch D/R, go to DTC P1899-A: PARK/NEUTRAL SWITCH STUCK IN PARK OR IN GEAR under DIAGNOSTIC TESTS. If scan tool displays P/N switch D/R, go to next step.
- Turn ignition off. Disconnect speed control servo connector. Inspect speed control servo connector for damaged or pushed out terminals. Repair as necessary. Perform TEST VER-4A: SPEED CONTROL VERIFICATION under VERIFICATION TESTS. If wiring and connectors are okay, go to next step.
- Using an external ohmmeter, measure resistance of ground circuit (Black wire) between speed control servo connector terminal No. 4 and ground. If resistance is 5 ohms or more, repair open ground circuit. Perform TEST VER-4A: SPEED CONTROL VERIFICATION under VERIFICATION TESTS. If resistance is less than 5 ohms, go to next step.
- Reconnect S/C servo connector. Turn ignition on. Using scan tool, actuate speed control vent solenoid. Using a 12-volt test light, backprobe S/C brake switch output circuit at S/C servo connector terminal No. 3 (Dark Blue/Red wire). If test light is not on or dim, go to NTC-4A: CHECKING BRAKE SWITCH SENSE . If test light is bright, go to next step.
- Start engine. Allow engine to idle for one minute. Turn engine off. Turn ignition on. Using scan tool, actuate speed control servo solenoids. If throttle opens and closes, go to NTC-5A: CHECKING PARK/NEUTRAL POSITION SWITCH SENSE . If throttle does not open and close, go to next step.
- Turn ignition off. Disconnect vacuum supply from speed control servo. Attach a vacuum gauge to disconnected vacuum hose. Start engine. If vacuum gauge does not read manifold vacuum, repair vacuum supply hose for a leak or restriction. Perform TEST VER-4A: SPEED CONTROL VERIFICATION under VERIFICATION TESTS. If vacuum gauge reads manifold vacuum, go to NTC-1C: CHECKING SPEED CONTROL OPERATION .