OBD-II trouble code
P0693: Fan 2 Control Circuit Low
The control circuit for the second cooling fan has been pulled toward ground. On most vehicles fan 2 is the condenser-side fan, so the complaint that actually brings the car in is usually air conditioning that quits at a stoplight — not an overheating engine.
Quick facts
- System
- Powertrain
- Category
- Cooling / Electrical
- Severity
- High severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $60 – $700
- DIY difficulty
- Intermediate DIY
What does P0693 mean?
A vehicle with two cooling fans almost never has two fans doing the same job. One of them is tied to engine coolant temperature and carries the cooling load the engine itself needs. The other is tied primarily to air conditioning demand and to refrigerant head pressure, sitting in front of the condenser and pulling air through it. Fan 2 is normally the second of those. That single assignment is what separates this code from the fan 1 codes, and it changes the complaint, the diagnosis and the argument about how urgent the repair is.
What the driver notices is rarely a temperature gauge. It is air conditioning that works perfectly on the motorway and then goes lukewarm the moment the vehicle stops moving, recovering again as soon as it is rolling. That symptom is produced by exactly the same physics that makes the fan necessary: at speed there is enough air passing through the condenser without help, and at a standstill there is none. So the system does not fail, it fails situationally, and it does so in a pattern that reads to almost everybody as low refrigerant.
This is worth being blunt about, because it is where the money goes wrong. A vehicle presenting with intermittent air conditioning gets a recharge quoted, sometimes performed, and the refrigerant was never low. The charge comes out at specification, the leak search finds nothing, and the fault returns on the next hot afternoon. The stored code was there the whole time. Before anything is done to the refrigerant circuit on a car that cools while moving and stops cooling at rest, the condenser fan should be watched with the air conditioning switched on, because that observation costs nothing and settles it.
The electrical fault itself is the low-side one. The module drives this circuit and watches the voltage on it; a reading pulled down toward ground when the module did not command that points at a short to ground in the wiring, a relay shorted or stuck low, or a driver fault inside the module. The physical location of the harness matters here in a way it does not on the engine-side fan. Fan 2's wiring runs to the very front of the vehicle, ahead of the radiator support and behind the grille, which is the part of the car that meets stones, road salt spray, insects, plastic underbody trays and the occasional minor front-end impact. It is also the wiring most often disturbed by bodywork, bumper removal and headlight or condenser replacement, so recent front-end work is a genuinely useful question to ask.
On the driving question, the honest answer has two halves rather than one. If fan 2 on this vehicle is purely the condenser fan, the engine will not overheat and the risk is to the air conditioning compressor, which is being asked to work against high head pressure with no airflow to relieve it — an expensive part to cook slowly. If the two fans instead share the engine cooling load, or if fan 2 is the one that comes on as coolant temperature climbs past the first threshold, then engine temperature genuinely is at stake in traffic. Since the assignment varies, the conservative approach is to treat stop-and-go driving as the thing to avoid and to switch the air conditioning off until the fan is working.
Common causes
- Fan 2 control wire shorted to ground where it runs ahead of the radiator support or behind the grille
- Fan 2 relay shorted internally or with contacts welded closed
- Front-end harness damaged by stone impact, road salt or a minor collision
- Wiring disturbed or pinched during bumper, condenser, headlight or intercooler work
- Condenser fan motor shorting internally and dragging the control circuit down
- Water tracking into the fan connector at the bottom of the fan shroud, where spray collects
- Corroded relay socket terminals in the underhood fuse box
- Failed module fan-2 driver, which should be the conclusion rather than the starting assumption
Symptoms
- Air conditioning blowing cold while driving and turning lukewarm at idle or in slow traffic
- Condenser fan not spinning with the air conditioning switched on and the engine warm
- Check engine light on, sometimes with no drivability complaint at all
- Engine temperature creeping up in traffic on vehicles where fan 2 shares the cooling load
- Air conditioning cutting out on its own on hot days and returning when the vehicle moves
- Blown fan-circuit fuse if the short to ground is a hard one
- Second fan running constantly from key-on in some short-to-ground failures
- No symptoms whatsoever at motorway speed
Diagnostic steps
- 1.Establish which fan is fan 2 on this specific vehicle before touching anything. Two fans do not have interchangeable roles and the wiring diagram, not the physical position, is what settles it.
- 2.Warm the engine, switch the air conditioning to maximum and watch both fans. A condenser fan that never starts while the compressor is engaged confirms the functional half of the complaint in under a minute.
- 3.Read the freeze frame and note whether the fault was captured at low road speed with the air conditioning on. That combination is the fingerprint of a condenser fan circuit and it narrows the search immediately.
- 4.Swap the fan 2 relay with an identical relay from a non-critical circuit and see whether the behaviour moves with it.
- 5.Unplug the relay and check the fan 2 control wire for continuity to ground with nothing commanding it. A grounded reading at rest is the short, confirmed.
- 6.Follow the harness across the front of the vehicle specifically, checking where it passes the radiator support, the shroud edge and any plastic air deflectors, and looking for stone chips and salt corrosion rather than heat damage.
- 7.Ask what front-end work the vehicle has had. A bumper, condenser, headlight or cooler job that pinched a wire is a far more common cause here than component failure.
- 8.Measure the fan motor's resistance and current draw before condemning wiring, since a motor breaking down internally can pull the circuit low on its own.
- 9.Check the refrigerant pressures only after the fan question is settled, so that a normal charge is not mistaken for evidence of something else.
Repair cost
$60 – $700
A cooling fan relay is $15 to $80 in parts and a relay-only repair comes to roughly $90 to $170 fitted. Repairing a chafed or corroded control wire across the front of the vehicle runs $120 to $350, and more if a bumper has to come off to reach it. A condenser fan motor or a complete fan-and-shroud assembly is $250 to $700 installed, since many are sold only as an assembly. The number worth keeping in view is the one you avoid: an air conditioning compressor run repeatedly against high head pressure with no condenser airflow is a $900 to $1,800 replacement, and a refrigerant recharge bought to chase this symptom is money spent on a system that was never low.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with cooling fan relay replacement preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
This is an intermediate DIY job. It usually involves diagnostic steps, specialty parts, and some careful work in tight spaces. If you have the tools and a service manual or trustworthy video for your specific vehicle, it is achievable in a weekend. Otherwise, a competent independent shop will be faster.