Pinpoint Test F: DTCs C1893 (LR) and C1885 (RR)
Vehicle Dynamic Suspension
Pinpoint Tests
Pinpoint Test F: DTCs C1893 (LR) and C1885 (RR)
Refer to Wiring Diagram Set 41, Vehicle Dynamic Suspension for schematic and connector information. Diagrams By Number
Normal Operation
The 2 rear height sensors receive a 5-volt reference voltage from the Vehicle Dynamics Module (VDM) along circuit LCL12 (VT/OG), both sensors share a common return path along circuit RCL12 (GN/WH). The RR sensor sends the suspension height voltage back to the VDM along circuit VCL12 (WH/VT). The LR sensor sends the suspension height voltage back to the module along circuit VCL13 (BN/BU). The VDM monitors the 2 height sensors and makes adjustments to the rear suspension based on sensor input.
- DTC C1883 (Air Suspension LR Height Sensor Circuit Failure) - With the ignition in the RUN position, if the height sensor is reading less than 0.5 volt or more than 4.5 volts, DTC C1883 will be set.
- DTC C1885 (Air Suspension RR Height Sensor Circuit Failure) - With the ignition in the RUN position, if the height sensor is reading less than 0.5 volt or more than 4.5 volts, DTC C1885 will be set.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Height sensor(s)
- VDM
PINPOINT TEST F: DTCs C1893 (LR) AND C1885 (RR)
NOTICE: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multi-meter probes.
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F1 CHECK THE AIR SUSPENSION HEIGHT SENSOR VOLTAGE PIDs
- Disable the air suspension system. Refer to Air Suspension System Disable/Enable Air Suspension System Disable/Enable.
- Connect the scan tool.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger VDM.
- Disconnect the sensor arm linkage from both rear air suspension height sensors.
- NOTE: The voltage will increase as the suspension is compressed.
- Slowly move the height sensors through their full range of travel up and down while monitoring the following PIDs:
- Left Rear Height Sensor Voltage (LR_HEIGHT)
- Right Rear Height Sensor Voltage (RR_HEIGHT)
- Do the voltages vary from approximately 0.50 volt and 4.50 volts?
Yes
INSPECT the height sensor electrical connector(s) for corrosion and damage, REPAIR as necessary. CLEAR the DTCs. REPEAT the self-test.
No
CONNECT the sensor arm linkages to the air suspension height sensors. GO to F2.
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F2 CHECK CIRCUIT VCL12 (VT/OG) FOR VOLTAGE
- Ignition OFF.
- Disconnect: Suspect Height Sensor.
- Ignition ON.
- For the LR height sensor, measure the voltage between LR height sensor C4092-3, circuit VCL12 (VT/OG), harness side and ground.
- For the RR height sensor, measure the voltage between RR height sensor C4093-3, circuit VCL12 (VT/OG), harness side and ground.
- Are 5 volts present?
Yes
GO to F3.
No
GO to Pinpoint Test B. Pinpoint Test B: DTC C1724
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F3 CHECK CIRCUITS VCL13 (BN/BU) AND VCL12 (WH/VT) FOR AN OPEN
- Ignition OFF.
- Disconnect: VDM C2131b.
- For the LR height sensor, measure the resistance between VDM C2131b-6, circuit VCL13 (BN/BU), harness side and LR height sensor C4092-2, circuit VCL13 (BN/BU), harness side.
- For the RR height sensor, measure the resistance between VDM C2131b-1, circuit VCL12 (WH/VT), harness side and RR height sensor C4093-2, circuit VCL12 (WH/VT), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to F4.
No
REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test.
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F4 CHECK CIRCUITS VCL13 (BN/BU) AND VCL12 (WH/VT) FOR A SHORT TO GROUND
- For the LR height sensor, measure the resistance between LR height sensor C4092-2, circuit VCL13 (BN/BU), harness side and ground.
- For the RR height sensor, measure the resistance between RR height sensor C4093-2, circuit VCL12 (WH/VT), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to F5.
No
REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test.
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F5 CHECK CIRCUITS VCL13 (BN/BU) AND VCL12 (WH/VT) FOR A SHORT TO VOLTAGE
- Ignition ON.
- For the LR height sensor, measure the voltage between LR height sensor C4092-2, circuit VCL13 (BN/BU), harness side and ground.
- For the RR height sensor, measure the voltage between RR height sensor C4093-2, circuit VCL12 (WH/VT), harness side and ground.
- Is any voltage present?
Yes
REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test.
No
GO to F6.
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F6 CHECK FOR SIGNAL RETURN SHORTED TO VOLTAGE
- For the LR height sensor, measure the voltage between LR height sensor C4093-1, circuit RCL12 (GN/WH), harness side and ground.
- For the RR height sensor, measure the voltage between RR height sensor C4092-1, circuit RCL12 (GN/WH), harness side and ground.
- Are 5 volts present?
Yes
GO to Pinpoint Test B. Pinpoint Test B: DTC C1724
No
GO to F7.
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F7 CHECK CIRCUIT RCL12 (GN/WH) FOR AN OPEN
- Ignition OFF.
- For the LR height sensor, measure the resistance between VDM C2131b-5, circuit RCL12 (GN/WH), harness side and LR height sensor C4092-1, circuit RCL12 (GN/WH), harness side.
- For the RR height sensor, measure the resistance between VDM C2131b-5, circuit VCL12 (WH/VT), harness side and RR height sensor C4093-2, circuit VCL12 (WH/VT), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to F8.
No
REPAIR circuit VCL12 (WH/VT). CLEAR the DTCs. REPEAT the self-test.
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F8 VERIFY HEIGHT SENSOR(S) OUTPUT VOLTAGE
- Connect: VDM C2131b.
- Connect: RH Height Sensor C4093 and LH Height Sensor C4092.
- Disable the air suspension system. Refer to Air Suspension System Disable/Enable Air Suspension System Disable/Enable.
- Back probe RR height sensor C4093-2, circuit VCL12 (WH/VT) and LR height sensor C4092-2, circuit VCL12 (WH/VT).
- Is the voltage reading the same as the sensor PID reading?
Yes
GO to F9.
No
INSTALL a new height sensor(s) and CALIBRATE both height sensors. REFER to Suspension Height Sensor Service and Repair, CLEAR the DTCs. REPEAT the self-test.
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F9 CHECK THE VDM CONNECTOR
- Disconnect: VDM C2131b.
- Check VDM C2131b for:
- corrosion.
- pushed-out pins.
- spread terminals.
- Connect: VDM C2131b.
- Make sure the connector is seated correctly then enable the air suspension system, operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new VDM. REFER to Vehicle Dynamics Module (VDM) Service and Repair. CLEAR the DTCs. REPEAT the self-test.
No
The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector.
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