What Does P1248 Mean?
DTC P1248 indicates the cold-start injector control timing or fuel quantity differs from what the PCM expects during a cold start event. The cold-start injector (or cold-start enrichment strategy) is not delivering the correct fuel volume at the proper time, resulting in poor cold-start performance. This is often a diesel-specific code related to glow plug or pre-injection timing.
Common Causes
30%
Cold-start injector clogged or partially restricted
25%
Faulty cold-start injector solenoid not responding to PCM commands
20%
Incorrect fuel rail pressure during cold start affecting injector delivery
15%
Engine coolant temperature sensor reading incorrectly, causing wrong enrichment strategy
10%
PCM cold-start calibration issue or software requiring update
Diagnostic Steps
1
Monitor cold-start injector actual vs. commanded fuel quantity using a scan tool during a cold start (engine must be fully cooled).
2
Check engine coolant temperature sensor reading with a scan tool and compare to actual coolant temperature with an infrared thermometer — a discrepancy will cause incorrect enrichment.
3
Measure fuel rail pressure during cranking and cold start — compare to manufacturer specification for cold-start fuel pressure target.
4
Test the cold-start injector solenoid for proper resistance and mechanical operation — listen for audible clicking when commanded.
5
Check for TSBs related to cold-start calibration updates for the specific engine and model year.
Estimated Repair Cost
$100 - $600
Parts + labor, varies by vehicle and location
DTC P1248 indicates the cold-start injector control timing or fuel quantity differs from what the PCM expects during a cold start event. The cold-start injector (or cold-start enrichment strategy) is not delivering the correct fuel volume at the proper time, resulting in poor cold-start performance....
The most common cause of P1248 (Start Of Cold Start Injector Control Difference) is: Cold-start injector clogged or partially restricted
Typical repair costs for P1248 range from $100 to $600, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Poor cold-start enrichment primarily causes extended cranking, rough idle after start, white smoke, and increased cold-start emissions. While not a direct safety hazard, a no-start condition in cold weather can leave the driver stranded.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1248 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Powertrain
System
Fuel Injection / Cold Start
Difficulty
Type
Manufacturer
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
