Pinpoint Test H: DTC C1A67:87 Or DTC U0073:00
Speed Control
Pinpoint Tests
Pinpoint Test H: DTC C1A67:87 Or DTC U0073:00
Refer to Wiring Diagram Set 31, Speed Control for schematic and connector information. Diagrams By Number
NOTE: The speed control sensor is also known as the forward looking sensor.
Normal Operation
The adaptive cruise control system is enabled when the vehicle speed is set and the speed control sensor, which is a radar unit, determines the distance and relative speed of the vehicle that is in the path of travel. The Cruise-Control Module (C-CM) receives the speed control sensor input over a dedicated Controller Area Network (CAN). The inputs are sent through circuits VMF04 (BN/BU) and VMF05 (GY/BU) from the speed control sensor to the C-CM. Voltage is supplied to the speed control sensor from the C-CM on circuit CMF10 (GN). Ground is provided by circuit GD123 (BK).
- DTC C1A67:87 (Forward Looking Sensor: Missing Message) - sets when the C-CM is missing messages from the speed control sensor.
- DTC U0073:00 (Lost Communication Bus "A" Off: No Sub Type Information) - sets when the C-CM detects the dedicated CAN bus is off.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- speed control sensor
PINPOINT TEST H: DTC C1A67:87 OR DTC U0073:00
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery.
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H1 CHECK THE DTCs FROM BOTH THE CONTINUOUS AND ON-DEMAND C-CM SELF-TESTS
- Ignition ON.
- Clear continuous DTCs from all modules.
- Ignition OFF.
- Ignition ON.
- Wait at least 10 seconds.
- Carry out the C-CM self-test.
- Check the C-CM DTCs from the continuous and on-demand self-tests.
- Is DTC C1A67:87 or DTC U0073:00 recorded?
Yes
GO to H2.
No
The system is operating correctly at this time. The DTC may have been set due to an intermittent fault condition. CHECK C-CM connector, speed control sensor connector and the dedicated CAN bus wire for corrosion. CLEAN and REPAIR if corrosion is present. CLEAR the DTCs. REPEAT the self-test.
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H2 CHECK THE SPEED CONTROL SENSOR GROUND CIRCUIT FOR AN OPEN
- Disconnect: Speed Control Sensor C1601.
- Disconnect: Negative Battery Cable.
- Measure the resistance between the speed control sensor C1601-2, circuit GD123 (BK/GY), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
GO to H3.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
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H3 CHECK FOR VOLTAGE AT THE SPEED CONTROL SENSOR
- Connect: Negative Battery Cable.
- Ignition ON.
- Measure the voltage between the speed control sensor C1601-1, circuit CMF10 (GN), harness side and ground; and between the speed control sensor C1601-5, circuit CMF10 (GN), harness side and ground.
- Are the voltages greater than 10 volts?
Yes
GO to H4.
No
REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.
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H4 CHECK THE SPEED CONTROL SENSOR DEDICATED CAN CIRCUITS FOR AN OPEN
- Disconnect: C-CM C3173.
- Connect a fused jumper wire between the C-CM C3173-2, circuit VMF05 (GY/BU), harness side and ground the C-CM C3173-3, circuit VMF04 (BN/BU), harness side.
- Measure the resistance between the speed control sensor C1601-3, circuit VMF05 (GY/BU), harness side and the speed control sensor C1601-4, circuit VMF04 (BN/BU), harness side.
- Is the resistance less than 5 ohms?
Yes
REMOVE the jumper wire. INSTALL a new speed control sensor. REFER to Speed Control Sensor Service and Repair. CLEAR the DTCs. REPEAT the self-test.
No
REMOVE the jumper wire. GO to H5.
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H5 CHECK CIRCUIT VMF04 (BN/BU) FOR AN OPEN
- Measure the resistance between the C-CM C3173-3, circuit VMF04 (BN/BU), harness side and the speed control sensor C1601-4, circuit VMF04 (BN/BU), harness side.
- Is the resistance less than 5 ohms?
Yes
REPAIR circuit VMF05 (GY/BU). CLEAR the DTCs. TEST the system for normal operation.
No
REPAIR circuit VMF04 (BN/BU). CLEAR the DTCs. TEST the system for normal operation.
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