P0385 on Cadillac: How to Diagnose & Fix
Crankshaft Position Sensor "B" Circuit Malfunction
2 Cadillac models · 2 documented issues · 2 critical · $150-$500 repair
P0385 on Cadillac by model: symptoms, diagnosis and fix
The dual crankshaft position sensors on the 2000-2002 Northstar (which feed the coil-on-plug PCM directly) develop cracked solder joints at an internal resistor, causing intermittent chuggle, stalling while driving, long cranking, or a hot no-start that often resolves once the engine cools. GM ran a voluntary emissions campaign on certain 2000 Eldorado and Seville 4.6L vehicles for this defect, and RepairPal documents it as a top Eldorado driveability problem. Because both sensors live behind the oil filter adapter and fail similarly, the accepted practice is replacing both at once.
Common Symptoms
- Intermittent stalling while driving, often restarting after the engine cools
- Long crank time or no-start when hot
- Engine chuggle or stumble at speed
- Check engine light with crank-sensor codes such as P0335 or P0385
- Tachometer drops to zero just before the stall
How to Fix
Replace both crankshaft position sensors (A and B) together, then perform the CKP system variation relearn with a Tech II-type scan tool. Typical independent-shop cost is roughly $200-$500 for both sensors including labor.
Sources for this issue (1)
The Northstar uses two crankshaft position sensors (commonly referred to as the upper/A and lower/B 24x sensors) mounted low on the block behind the oil filter adapter area. The original Siemens-sourced sensors are widely reported by DeVille owners to fail with age and heat, setting a Service Engine Soon light with crank sensor circuit codes, causing hard starting, intermittent stalling, and eventually a no-start. Failures are often intermittent for weeks before becoming permanent, and heat-soak after a hot restart is a common trigger. Owners note the sensor connectors and their pigtails also corrode, producing the same codes with a good sensor installed. A crankshaft variation relearn is required after replacement or the SES light returns even with new parts.
Common Symptoms
- Service Engine Soon light
- Extended cranking or no-start
- Intermittent stalling while driving
- Hard restart when hot
- Rough running or misfire feel
How to Fix
Confirm the crank-sensor fault and replace both upper and lower sensors together, inspect connectors and O-rings, then perform the CKP variation relearn. Do not treat one linked sensor as the complete repair.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine GM 12575481 upper crankshaft-position sensor$61
2000-2005 Cadillac DeVille 4.6L V8 upper sensor only. The repair requires the matching lower sensor 12575482/ACDelco 213-1579 as well; the browser-opened OEM lower-sensor destination was unavailable and is intentionally not linked.
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Sources for this issue (3)
P0385 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0385 mean on a Cadillac?
P0385 stands for "Crankshaft Position Sensor "B" Circuit Malfunction." P0385 indicates a fault in the electrical circuit of the secondary ("B") crankshaft position sensor. The engine control module (ECM) has detected a signal from this sensor that is out of range, intermittent, or missing, which can disrupt accurate timing of fuel injection and ignition. On Cadillac it is documented across 2 models: Eldorado, DeVille.
What are the most common causes of P0385?
The most common causes of P0385 are: Faulty crankshaft position sensor 'B', Damaged, corroded, or loose sensor wiring/connector, Open or short circuit in the CKP sensor harness, Damaged reluctor/tone ring teeth on the crankshaft, Metal debris on the sensor tip or excessive air gap, Faulty ECM/PCM (less common). The specific cause varies by vehicle.
How much does it cost to fix P0385 on a Cadillac?
Published repair estimates on Cadillac range from $150 to $500 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0385 on a different make?
View P0385 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.