What Does C1870 Mean?
The air suspension gate solenoid output circuit has been detected as open. The electrical path to the gate (exhaust/vent) solenoid is broken, preventing the control module from commanding the valve. The system cannot vent air from the springs, so the vehicle may be stuck at ride height or above, and the suspension warning light will illuminate.
Common Causes
35%
Burned-out solenoid coil in the gate valve due to age, contamination, or overuse
30%
Broken wire or severed conductor in the gate solenoid wiring harness
20%
Disconnected, backed-out, or corroded connector pin at the gate solenoid or module connector
15%
Control module internal open circuit on the gate solenoid driver output
Diagnostic Steps
1
Unplug the gate solenoid connector and measure coil resistance across the terminals. Should read 8-15 ohms. An open (infinite) reading means the coil is burned out and the solenoid must be replaced.
2
If coil resistance is normal, perform continuity tests on both wires from the solenoid connector to the module connector. An open wire will read infinite resistance.
3
Inspect all connector pins at the solenoid and module ends. Look for pins that have backed out of the connector housing, are bent, or show green/white corrosion deposits.
4
Trace the harness visually from the solenoid to the module. Check at clip points, grommets, and anywhere the harness crosses frame members or moving parts.
5
If all external circuits check good, test the module's output driver by commanding the solenoid on and measuring for a ground-switching signal at the module connector.
Estimated Repair Cost
$150 - $700
Parts + labor, varies by vehicle and location
The air suspension gate solenoid output circuit has been detected as open. The electrical path to the gate (exhaust/vent) solenoid is broken, preventing the control module from commanding the valve. The system cannot vent air from the springs, so the vehicle may be stuck at ride height or above, and...
The most common cause of C1870 (Air Suspension Gate Solenoid Output Circuit Open) is: Burned-out solenoid coil in the gate valve due to age, contamination, or overuse
Typical repair costs for C1870 range from $150 to $700, depending on the vehicle, location, and whether you do it yourself or go to a shop.
The vehicle cannot vent air from the suspension, which may cause it to ride too high or prevent lowering for entry/exit. Handling characteristics change with elevated ride height. The vehicle is drivable but should be repaired promptly, especially if operating at elevated ride height on the highway where crosswind sensitivity is increased.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to C1870 to identify the root cause.
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Quick Info
Category
Chassis
System
Air Suspension
Difficulty
Type
Manufacturer
Recommended Tools
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