Pinpoint Test 1: The Speed Control Is Inoperative

PINPOINT TEST 1: THE SPEED CONTROL IS INOPERATIVE

Normal Operation
The speed control actuator sends and receives signals to the speed control switches through circuits (W) and (G/BR). Voltage to the speed control actuator is supplied through circuit (Y/GY) from the smart junction box (SJB). Ground for the speed control actuator is through circuit (B/G).

Voltage for the speed control servo clutch (internal to the speed control actuator) is supplied by the SJB to the speed control deactivator switch through circuit (V/BR). The speed control deactivator switch (closed when the brake pedal is not applied) then routes the voltage through circuit (V/O) to the speed control actuator. When the brake pedal is firmly pressed, the speed control deactivator switch opens and voltage is no longer supplied to the speed control servo clutch.

When the brake pedal is applied, the stoplamp switch routes voltage to circuit (V/W) to illuminate the stoplamps and send a voltage signal to the speed control actuator. When the speed control actuator receives this input, the speed control actuator goes into a stand-by mode.

The speed control actuator sends a voltage reference signal through circuit (G/W). The speed control system will not engage if circuit (G/W) is grounded, and goes into a stand-by mode if the speed control system has a set speed that it is maintaining. When the transaxle is placed in NEUTRAL (N) (automatic transaxle), the digital transmission range (TR) sensor routes the signal to ground through circuit (B/G). When the clutch is applied (manual transaxle), the clutch pedal position switch (CPP) routes the signal to ground through circuit (Y/V) and then to the powertrain control module (PCM). The PCM provides a ground internally for this circuit.

The speed control actuator receives the speed signal from the PCM through circuit (V/O).

Possible Causes
- Fuse
- Wiring, terminals or connectors
- CPP switch
- TR sensor
- Speed control deactivator switch
- Speed control cable
- Throttle body linkage
- Speed control switches
- Clockspring
- Speed control actuator
- SJB
- PCM

Diagnostic Procedure

CAUTION: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

NOTE: It is important to use a voltage drop test on some of the tests where specified. Circuits may indicate a good voltage and continuity but may not be capable of carrying sufficient current.

Step 1:

Step 2-Step 5:

Step 6-Step 9:

Step 10-Step 13:

Step 14-Step 19:

Step 20-Step 24:

Step 25-Step 29:

Step 30:

Step 31-Step 33: