C1807 — Vent Solenoid Supply Short to Positive

C1807 — Vent Solenoid Supply Short to Positive. C1807 is generally not an immediate power or braking failure, so limited driving may be possible if the engine runs normally.

For Ford vehicles

vent solenoid valve supply – short to positive supply

vehicle

Is it safe to drive?

Arrange prompt repair C1807 is generally not an immediate power or braking failure, so limited driving may be possible if the engine runs normally. However, a vent-solenoid fault can affect fuel-vapor control; repair it promptly and stop in a safe open area if a strong fuel odor appears.

Typical symptoms

C1807 remains stored in the vehicle control module and may illuminate the check-engine light.
The EVAP vent solenoid may fail to open when the control module commands purging.
A fuel-vapor odor may be present near the fuel-filler area or inside the cabin.
Trapped evaporative pressure can cause difficulty starting after the vehicle has sat for several hours.
The EVAP system monitor may show an incomplete or failed test cycle.

Common causes

C1807 can result from a vent solenoid valve whose internal winding has shorted within its positive-supply circuit.
A chafed or abraded harness conductor may be contacting another constant-positive wire.
A damaged connector terminal can bridge the vent-solenoid supply to a battery-positive pin.
Pinched wiring from a previous repair or nearby component movement can create the short.
Corrosion or moisture inside the connector may allow current to leak between positive-supply and valve terminals.

How to diagnose with an OBD scanner

Confirm C1807 with a scan tool Connect an ELM327 device with AIScanAuto or another capable scanner, then read stored and pending codes. Confirm C1807 and record its freeze-frame data, including whether the fault appears during an EVAP vent-solenoid command.
Inspect the connector and harness Examine the vent solenoid connector, terminals, and nearby wiring for damaged insulation, pinched wires, water intrusion, green corrosion, or evidence that a terminal is tied into a positive-supply circuit.
Perform circuit isolation tests Use the vehicle wiring diagram to isolate the suspect conductor. With power removed, perform continuity tests to battery positive and ground; an unintended near-zero-ohm path to positive confirms the short condition described by C1807.
Test the vent solenoid separately Disconnect the solenoid and repeat the appropriate supply-to-positive test. If the short disappears with the solenoid isolated, compare its resistance with the service specification and replace it if the internal winding is shorted. If the short remains, repair the harness or connector.
Check the module-side circuit If the wiring and solenoid test normally, inspect the control-module connector and use manufacturer-specific diagnostic procedures to verify the output. Do not replace the module solely because C1807 is present without completing these checks.
Clear and verify the repair After correcting the short, clear C1807 with the scanner and monitor EVAP commands if supported. Command the vent solenoid with an actuator test when available, then road-test and confirm that C1807 does not return and the EVAP monitor completes.

Approximate repair cost

A rough independent-shop estimate for diagnosing and repairing C1807 is approximately USD 100–350, depending on whether the fault is the solenoid, connector, or harness. These figures are estimates and vary by region, vehicle configuration, and parts availability; obtain a local written quote before repair.

Common questions

What does code C1807 specifically mean?

C1807 identifies a short-to-positive condition involving the vent solenoid valve supply circuit. The fault may be within the solenoid, its connector, or the wiring connected to that circuit.

Can the vehicle be driven with C1807 stored?

Short trips may be possible if there is no fuel odor, abnormal idle, or starting difficulty, but C1807 should be diagnosed promptly because the vent circuit may not control fuel vapor correctly.

Does C1807 prove that the vent valve is mechanically stuck?

No. C1807 describes an electrical short to the positive supply. A stuck vent valve can cause separate EVAP symptoms or codes, but those conditions should not be assumed without additional testing.

What is the usual repair for C1807?

The usual procedure is to isolate the circuit, test the vent solenoid separately, inspect the connector and harness, and repair the failed component or damaged wiring before clearing C1807 and verifying EVAP operation.

C1807 — C1807 — Manufacturer Controlled DTC: Causes, Symptoms & Fix

When your scan tool pulls code C1807, you're looking at a fault logged by the vehicle's control module in the manufacturer-specific portion of the OBD2 system. This isn't a generic powertrain code—it lives in theautomaker-defined section and signals a problem with sensor or actuator circuit operation. The module won't set C1807 after a single bad reading; it waits until the fault condition repeats under specific operating parameters. That means when you pull this code, you also get freeze frame data: engine load, RPM, coolant temperature, and vehicle speed captured at the moment the problem occurred. Use those numbers to your advantage—recreate those exact conditions during your diagnosis.

The exact system affected by C1807 varies between manufacturers, but the underlying issue is consistent: the control module has detected a fault in how it sends or receives signals from a circuit. This could stem from a bad ground, damaged wiring, a failing component, or a poor connection. Because C1807 requires multiple fault occurrences before illuminating the check engine light, the problem is often intermittent—appearing under certain temperatures, loads, or driving conditions before vanishing.

Symptoms of C1807

The system tied to this circuit operates inconsistently or stops working entirely
Vehicle may enter limp mode, limiting power and speed depending on which component is affected
Fuel economy often drops as the ECU compensates for missing or erratic sensor data
Check Engine Light remains on after the fault condition repeats
Possible stalling or hard-starting if the affected circuit is critical to engine operation
In some cases, additional trouble codes accompany C1807, pointing to downstream effects

Common Causes

Damaged, corroded, or loose electrical connector interrupting signal or power
Poor ground connection at the affected component or control module
Open or shorted wiring within the circuit from physical damage or age
Faulty sensor or actuator receiving or sending incorrect signals
Control module internal failure affecting its ability to process circuit data
Wire chafing where harness rubs against frame or engine components

How to Diagnose C1807

Connect your OBD2 scanner, confirm C1807 is stored, and record all freeze frame data—this shows you exactly what was happening when the module first flagged the fault.
Check for related trouble codes and search manufacturer TSBs by VIN on the automaker website or NHTSA database; many C0xxx codes have documented factory fixes or software updates that save diagnostic time.
Perform a visual inspection of the harness and connectors associated with this circuit—look for damaged insulation, bent pins, moisture intrusion, or corrosion buildup that could block proper electrical contact.
With a multimeter, check reference voltage, ground circuit resistance, and signal continuity at the component connector to verify each electrical parameter falls within specification.
Conduct a wiggle test on the harness while monitoring live data on your scanner—signal dropouts or irregularities point to broken wires that only fail under movement or vibration.
Clear C1807, then drive the vehicle through the exact conditions recorded in the freeze frame and verify the code does not return.

Repair Options and Costs

Address the most affordable and probable causes before committing to expensive part replacement:

Repair or replace damaged wiring and connectors: $80–$250
Replace faulty sensor or actuator component: $150–$500
Control module diagnosis and repair: $300–$1,000

Total Repair Cost

The final bill for C1807 depends entirely on which part of the circuit failed. Independent shop labor rates typically add $75–$150 per hour on top of parts costs. Most C1807 repairs fall between $80 and $1,000 total. Always pursue an accurate diagnosis before purchasing components—an expensive control module is rarely the culprit, yet it tempts anyone who skips the basics. A thorough electrical verification upfront prevents replacing parts that weren't broken in the first place.

Can You Drive with C1807?

In most cases, the vehicle remains drivable with C1807 stored, though you may notice reduced performance or a disabled auxiliary system. If the malfunction causes stalling, no-start conditions, or triggers warnings related to braking or steering, treat it as urgent and stop driving immediately. Otherwise, schedule repair at your earliest convenience—continuing to drive with an unresolved circuit fault can cause the module to enter permanent default mode or damage related components.