Pinpoint Test G: The Speed Control Indicator Lamp Is Always On
Speed Control
Pinpoint Tests
Pinpoint Test G: The Speed Control Indicator Lamp Is Always On
Refer to wiring Diagram Set 31, Speed Control for schematic and connector information. Diagrams By Number
Normal Operation
When the speed control is engaged, the speed control actuator grounds circuit CES03 (VT/WH) to the Smart Junction Box (SJB). The Instrument Cluster (IC) receives the speed control status from the SJB over the High Speed Controller Area Network (HS-CAN) communication bus. When the speed control has been engaged, the SJB sends a message to the IC to illuminate the speed control indicator. When the speed control is disengaged, the speed control actuator removes the ground to turn the indicator lamp off.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Speed control actuator
- IC
- SJB
PINPOINT TEST G: THE SPEED CONTROL INDICATOR LAMP IS ALWAYS ON
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connectors.
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G1 CHECK THE SPEED CONTROL ACTUATOR
- Ignition OFF.
- Disconnect: Speed Control Actuator C122.
- Ignition ON.
- Check the speed control indicator lamp.
- Does the speed control indicator lamp remain on?
Yes
GO to G2.
No
INSTALL a new speed control actuator. REFER to Speed Control Actuator Service and Repair. TEST the system for normal operation.
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G2 CHECK THE SPEED CONTROL INDICATOR CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: SJB C2280a.
- Measure the resistance between the speed control actuator C122-1, circuit CES03 (VT/WH), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
REFER to Instrument Panel, Gauges and Warning Indicators to continue diagnosis of the speed control indicator.
No
REPAIR the circuit. TEST the system for normal operation.
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