Pinpoint Test D: DTC C1770
Vehicle Dynamic Suspension
Pinpoint Tests
Pinpoint Test D: DTC C1770
Refer to Wiring Diagram Set 41, Vehicle Dynamic Suspension for schematic and connector information. Diagrams By Number
Normal Operation
The Vehicle Dynamics Module (VDM) will command the air suspension system vent solenoid ON or OFF when certain conditions are met. The VDM supplies voltage to the vent solenoid through circuit CCL14 (BN/VT), which activates the vent solenoid and vents the air suspension system. The vent solenoid is grounded through circuit GD123 (BK/GY).
The vent solenoid is part of the air suspension compressor, if a new vent solenoid is needed, an air suspension compressor must be installed.
- DTC C1770 Air Suspension Vent Solenoid Output Circuit Failure - With the ignition in the RUN position and during a deflate (vent) activity, if the VDM detects an open, a short to voltage or a short to ground on the vent solenoid output circuit, DTC C1770 will be set.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Air suspension compressor
- VDM
PINPOINT TEST D: DTC C1770
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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D1 CHECK THE VENT SOLENOID PIDs
- Connect the scan tool.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger VDM.
- Monitor the following VDM PIDs:
- Vent solenoid output open circuit (VSOL_RLY_OC)
- Vent solenoid output short to battery (VSOL_RLY_STB)
- Vent solenoid output short to ground (VSOL_RLY_STG)
- Do any of the PIDs display "Yes"?
Yes
For a short to ground, GO to D3.
For a short to voltage, GO to D4.
For an open circuit, GO to D2.
No
The condition is not present at this time. CLEAR the DTCs. REPEAT the self-test.
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D2 CHECK CIRCUIT GD123 (BK/GY) FOR AN OPEN
- Ignition OFF.
- Disable the air suspension system. Refer to Air Suspension System Disable/Enable Air Suspension System Disable/Enable.
- Disconnect: Air Suspension Compressor C1179.
- Measure the resistance between air compressor assembly C1179-3, circuit GD123 (BK/GY), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
INSPECT the air suspension compressor C1179 for corrosion and damage.
If the connector is corroded or damaged, REPAIR as necessary.
If the connector is OK, GO to D5.
No
REPAIR circuit GD123 (BK/GY). CLEAR the DTCs. REPEAT the self-test.
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D3 CHECK THE VENT CONTROL CIRCUIT FOR A SHORT TO GROUND
- Disable the air suspension system. Refer to Air Suspension System Disable/Enable Air Suspension System Disable/Enable.
- Ignition OFF.
- Disconnect: Air Suspension Compressor C1179.
- Disconnect: VDM C2131a.
- Disable the air suspension system. Refer to Air Suspension System Disable/Enable Air Suspension System Disable/Enable.
- Measure the resistance between air compressor C1179-4, circuit CCL14 (BN/VT), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to D5.
No
REPAIR circuit CCL14 (BN/VT).
CLEAR the DTCs. REPEAT the self-test.
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D4 CHECK THE VENT CONTROL CIRCUIT FOR A SHORT TO VOLTAGE
- Disable the air suspension system. Refer to Air Suspension System Disable/Enable Air Suspension System Disable/Enable.
- Ignition OFF.
- Disconnect: Air Suspension Compressor C1179.
- Disconnect: VDM C2131a.
- Ignition ON.
- Measure the voltage between air compressor C1179-4 circuit CCL14 (BN/VT) harness side and ground.
- Is any voltage present?
Yes
REPAIR circuit CCL14 (BN/VT). CLEAR the DTCs. REPEAT the self-test.
No
GO to D6.
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D5 CHECK THE VENT SOLENOID FOR AN OPEN OR A SHORT
- Measure the resistance between air compressor C1179 pin-4, component side and C1179 pin-3, component side.
- Is the resistance between 17 and 22 ohms?
Yes
GO to D6.
No
INSTALL a new air compressor. REFER to Air Suspension Compressor Service and Repair. CLEAR the DTCs. REPEAT the self-test.
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D6 CHECK THE VDM CONNECTOR
- Ignition OFF.
- Check VDM C2131a for:
- corrosion.
- pushed-out pins.
- spread terminals.
- Connect: VDM C2131a.
- Make sure the connector is seated correctly then 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. Both height sensors must be calibrated. RESET the vehicle ride height. REFER to Ride Height Adjustments Ride Height Adjustments.
No
The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector.
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