Can I drive with P0683?

Usually yes once the engine runs, but cold starts may be long or fail. Get it checked before cold weather.

Can a bad glow plug cause P0683?

It is not the usual cause. A dead plug normally sets its own cylinder code (P0671 to P0674), while P0683 points at the link between the module and the engine control unit. Some code references still list failed plugs as a cause, so test the plugs with a multimeter before paying for a module.

What is the difference between P0683 and P0670?

P0670 points at a fault in the glow plug control module circuit itself, while P0683 is about the communication between the module and the engine control unit.

How much does it cost to fix P0683?

A fuse costs a few euros and a connector repair about 45-150 EUR. One glow plug is 50-150 EUR, a set 100-500 EUR and a control module about 120-370 EUR fitted.

P0683: Glow Plug Control Module to PCM Communication Circuit

Quick Answer

Safe to drive (short-term)

P0683 is a diesel-only code meaning the engine control unit could not communicate correctly with the glow plug control module, the unit that switches power to the glow plugs for cold starts. Wiring and connectors between the two, the module's fuse and power supply, low battery voltage and the module itself are the usual suspects. The engine control unit is rarely the cause.

Severity: Moderate · Electrical
Estimated repair cost: From €2 to €500+, varies by vehicle

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What does P0683 mean?

P0683 is a electrical-related diagnostic trouble code classified as moderate severity. When your vehicle's ECU detects this condition, it stores P0683 and illuminates the check engine light.

What are the symptoms of P0683?

If your vehicle has triggered P0683, you may notice one or more of these symptoms:

Check engine light or glow plug lamp on or flashing
Hard starting or no start in cold weather
Long cranking and white smoke on cold starts
Rough idle for the first minute
Reduced power on some engines
Higher emissions until the engine warms up

What causes P0683?

Here are the most common causes of P0683:

Damaged, corroded or loose wiring or connector between the module and the engine control unit
: high
Blown fuse or fusible link in the glow plug module supply
: medium
Low battery voltage
: medium
Failed glow plug control module
: medium
One or more failed glow plugs
: low
Faulty engine control unit (rare)
: low

Is it safe to drive with P0683?

Generally yes, for short-term driving. Usually safe to drive once the engine is running. The fault affects cold starting, so expect long cranking, white smoke or a no-start on cold mornings. If the car will not start or stalls, do not keep cranking the starter; have the cause checked before winter.

How do you diagnose P0683?

Follow these steps to pinpoint the root cause of P0683:

Read all stored codes and the freeze frame with an OBD2 reader. A per-cylinder glow plug code (P0671 to P0674) or a battery voltage code stored alongside often shows where to start
Low battery voltage is listed among the causes, so test the battery and charging voltage before anything else
Check the glow plug fuses and fusible links, and inspect the module connector for corrosion, burnt or loose pins
Measure each glow plug with a multimeter. Most read a few ohms or less, and an open circuit reads infinite. A dead plug normally sets its own cylinder code and is worth replacing while the car is in
Check the wire or data line between the module and the engine control unit for continuity and shorts, against the wiring diagram
Replace the module only when its supply, ground and the link wiring have tested good. Per-plug status data is manufacturer-specific and not readable with a generic reader

How much does P0683 cost to fix?

Repair costs for P0683 vary depending on the root cause and your vehicle. Here are typical estimates:

Repair	Parts Cost	Labor Cost	Total Estimate	DIY Difficulty
Replace glow plug fuse (DIY)	€2–€10	€0–€0	€2–€10	Easy
Repair wiring or connector to the module	€5–€30	€40–€120	€45–€150	Moderate
Replace one glow plug	€10–€40	€40–€110	€50–€150	Moderate
Replace glow plug set (four cylinders)	€40–€120	€60–€380	€100–€500	Moderate
Replace glow plug control module	€60–€220	€60–€150	€120–€370	Moderate

Prices estimated as of March 2026. Costs vary by region, vehicle, and shop.

These codes are often seen alongside P0683 or indicate related issues:

Common questions about P0683

What does P0683 mean?: P0683 means the engine control unit lost or could not get valid communication with the glow plug control module. It only applies to diesel engines.
Can I drive with P0683?: Usually yes once the engine runs, but cold starts may be long or fail. Get it checked before cold weather.
Can a bad glow plug cause P0683?: It is not the usual cause. A dead plug normally sets its own cylinder code (P0671 to P0674), while P0683 points at the link between the module and the engine control unit. Some code references still list failed plugs as a cause, so test the plugs with a multimeter before paying for a module.
What is the difference between P0683 and P0670?: P0670 points at a fault in the glow plug control module circuit itself, while P0683 is about the communication between the module and the engine control unit.
How much does it cost to fix P0683?: A fuse costs a few euros and a connector repair about 45-150 EUR. One glow plug is 50-150 EUR, a set 100-500 EUR and a control module about 120-370 EUR fitted.

Read our detailed guides

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