LogalyzerEarly Access

CRITICAL ISSUES DETECTED — 1 critical violation found. Review immediately before driving.
DS1 4.0L V8 TFSI
2025-10-03_21.58.11_log.csv (Demo)
May 5, 2026 at 1:57 AM
Critical
1
Warnings
3

System Checks

✓
HPF Fuel Pressure
HPF: 1.0-14.4 MPa (Avg: 5.1 MPa) | Min safe: 11 MPa
✓
LPF Fuel Pressure
LPF: 520-721 kPa (Avg: 642 kPa) | Min safe: 400 kPa
✓
Knock Detection
No significant knock detected across all cylinders
✓
Lambda/AFR
Lambda: 0.776-15.940 (Avg: 6.404) | Safe range: 0.75-0.925
▲
Boost Control
Boost control issues detected
4 violations
✓
Charge Temperature
Measured: 50.2-71.2°C (Avg: 58.3°C) | Safe <60°C
✓
Injector Duty Cycle
Injectors operating below maximum duty cycle
✓
Long-Term Fuel Trim
LTFT within ±10% range - no persistent mechanical issues
✓
Short-Term Fuel Trim (Idle)
STFT within ±5% at idle conditions
✓
Short-Term Fuel Trim (Multiplicative)
Multiplicative STFT within ±15%

Issues Found

Boost Deviation - Warning

warning 3x

Boost pressure deviating >200 hPa from target.

Check for boost leaks

Verify wastegate actuators move freely

Check wastegate actuator length

Check exhaust for obstruction

Check turbo shaft play

Check intake filters

Consider intake upgrade

Consider turbo upgrade

Underboost Sustained

critical 1x

Boost >500 hPa below target for over 2 seconds - possible boost leak, wastegate issue, or turbo failure.

Sustained underboost detected - investigate immediately

Pressure-test the entire intake tract for boost leaks (charge pipes, intercooler, couplers)

Inspect wastegate actuators - stuck open or weak spring will bleed boost

Check turbo compressor wheel for damage or excessive shaft play

Verify diverter valves are holding pressure and not venting under load

Check exhaust system for restrictions (catalytic converter, downpipe)

If WGDC is already at 100%, turbos may be undersized for the tune's boost target

Notes

Violation Detail

Boost Deviation - Warning (3)
Time Severity Message Details
18.60s warning Underboost - boost below target over 200 hPa Duration: 1.49s (136 entries)
Condition: UNDERBOOST - Boost is 869 hPa below target (possible leak)
Boost Actual: 2084 hPa
21.03s warning Underboost - boost below target over 200 hPa Duration: 3.31s (299 entries)
Condition: UNDERBOOST - Boost is 400 hPa below target (possible leak)
Boost Actual: 2554 hPa
24.58s warning Underboost - boost below target over 200 hPa Duration: 3.68s (334 entries)
Condition: UNDERBOOST - Boost is 366 hPa below target (possible leak)
Boost Actual: 2588 hPa
Underboost Sustained (1)
Time Severity Message Details
18.77s critical Sustained underboost - boost >500 hPa below target for >3 seconds Duration: 4.82s (323 entries)
Condition: SUSTAINED UNDERBOOST - Boost is 832 hPa below target
Boost Actual: 2120 hPa

Diagnostic Graphs

Pull #1 Analysis

Analysis of pull from 17.03s to 26.74s

Knock Summary - NORMAL KNOCK at HIGH LOAD

Overall knock assessment: NORMAL KNOCK at HIGH LOAD (worst knock: -2.20°)

  • Worst knock timing reduction: -2.20°
  • Assessment: NORMAL KNOCK at HIGH LOAD
  • Green bars: No knock or acceptable knock
  • Orange/Red bars: Concerning knock levels requiring attention

Knock Timeline - All Cylinders

Individual cylinder knock behavior throughout the datalog with load overlay

  • Shows timing retard for each cylinder over time
  • Load shown as grey background area
  • Yellow line: -3.5° warning threshold
  • Look for patterns: which cylinders knock most, at what load levels

HPF Fuel Pressure - System Check

High pressure fuel system with engine load overlay

LPF Fuel Pressure - System Check

Low pressure fuel system maintained 520.0-720.9 kPa (threshold: 400 kPa minimum under load)

Lambda/AFR - System Check

Air-fuel ratio remained within safe range throughout datalog

Boost Control - System Check

[WARNING] Boost control issues detected — 4 violation events detected

Charge Air Temperature - System Check

Intake air temp after intercooler: 50.2-71.2°C (Avg: 58.3°C) | Safe <50°C, Warning 60°C, Critical >70°C

Long-Term Fuel Trim (LTFT) - System Check

LTFT represents learned fuel corrections - should stay within ±10% (±2% is normal for healthy systems per DS1 manual)

Short-Term Fuel Trim Additive - System Check

STFT Additive shows real-time fuel corrections - should be minimal at idle (±5% threshold)

Short-Term Fuel Trim Multiplicative - System Check

STFT Multiplicative corrects for airflow measurement errors - large values indicate MAP/IAT sensor miscalibration

Overview: 4 Total Violations

  • #1: Underboost Sustained (CRITICAL) @ 18.77s Sustained underboost - boost >500 hPa below target for >3 seconds • Duration: 4.82s (323 entries) • Condition: SUSTAINED UNDERBOOST - Boost is 832 hPa below target • Boost Actual: 2120 hPa • Boost Target: 2952 hPa • Deviation: 832 hPa • Wastegate Duty: 100.0% • Engine Load: 163.9%
  • #2: Boost Deviation - Warning (WARNING) @ 18.60s Underboost - boost below target over 200 hPa • Duration: 1.49s (136 entries) • Condition: UNDERBOOST - Boost is 869 hPa below target (possible leak) • Boost Actual: 2084 hPa • Boost Target: 2953 hPa • Deviation: 869 hPa • Wastegate Duty: 100.0% • Engine Load: 161.0%
  • #3: Boost Deviation - Warning (WARNING) @ 21.03s Underboost - boost below target over 200 hPa • Duration: 3.31s (299 entries) • Condition: UNDERBOOST - Boost is 400 hPa below target (possible leak) • Boost Actual: 2554 hPa • Boost Target: 2954 hPa • Deviation: 400 hPa • Wastegate Duty: 100.0% • Engine Load: 197.6%
  • #4: Boost Deviation - Warning (WARNING) @ 24.58s Underboost - boost below target over 200 hPa • Duration: 3.68s (334 entries) • Condition: UNDERBOOST - Boost is 366 hPa below target (possible leak) • Boost Actual: 2588 hPa • Boost Target: 2953 hPa • Deviation: 366 hPa • Wastegate Duty: 100.0% • Engine Load: 196.9%

Violation #1: Boost Deviation - Warning (Row 1530)

Underboost - boost below target over 200 hPa

  • Duration: 1.49s (136 entries)
  • Condition: UNDERBOOST - Boost is 869 hPa below target (possible leak)
  • Boost Actual: 2084 hPa
  • Boost Target: 2953 hPa
  • Deviation: 869 hPa
  • Wastegate Duty: 100.0%
  • Engine Load: 161.0%

Violation #2: Underboost Sustained (Row 1545)

Sustained underboost - boost >500 hPa below target for >3 seconds

  • Duration: 4.82s (323 entries)
  • Condition: SUSTAINED UNDERBOOST - Boost is 832 hPa below target
  • Boost Actual: 2120 hPa
  • Boost Target: 2952 hPa
  • Deviation: 832 hPa
  • Wastegate Duty: 100.0%
  • Engine Load: 163.9%

Violation #3: Boost Deviation - Warning (Row 1750)

Underboost - boost below target over 200 hPa

  • Duration: 3.31s (299 entries)
  • Condition: UNDERBOOST - Boost is 400 hPa below target (possible leak)
  • Boost Actual: 2554 hPa
  • Boost Target: 2954 hPa
  • Deviation: 400 hPa
  • Wastegate Duty: 100.0%
  • Engine Load: 197.6%

Violation #4: Boost Deviation - Warning (Row 2070)

Underboost - boost below target over 200 hPa

  • Duration: 3.68s (334 entries)
  • Condition: UNDERBOOST - Boost is 366 hPa below target (possible leak)
  • Boost Actual: 2588 hPa
  • Boost Target: 2953 hPa
  • Deviation: 366 hPa
  • Wastegate Duty: 100.0%
  • Engine Load: 196.9%

Load vs Load Limit - Full Datalog

Shows entire datalog - indicates if ECU is limiting load due to protection systems

  • Load (blue): Actual engine load throughout datalog
  • Load Limit (orange): ECU-imposed load limit from protection systems
  • Red lines: Violation timestamps
  • When Load matches Load Limit, ECU is actively restricting power

Ethanol Content Analysis

Fuel Type

E44

Range

43% - 46%

Fuel System Status

Healthy

Running E44 blend with good fuel system performance. No fuel pressure concerns detected.

Ethanol Content

Ethanol percentage variation throughout the datalog

Low Pressure Fuel (LPF) Analysis

LPF actual vs target with engine load overlay

High Pressure Fuel (HPF) Analysis

HPF actual vs target (both banks) with engine load overlay

Injector Pulse Width Analysis

Injector pulse width shows all cylinders within RPM-based limits

  • Maximum Pulse Width: 8.00 ms
  • Critical Threshold: RPM-based dynamic limit (30ms@0RPM, 15ms@4000RPM, 10ms@8000RPM) - only checked at load >140%
  • Status: Within Limits

Diagnostic Trouble Codes (DTC)

MIL (Check Engine)

None

Pending Codes

1 Code

OBD Visible

None

Tester Visible

1 Code

All Detected DTCs (1 Total)

711 (ISO Format)
First Failed Recent Failed

ℹ️ DTC Types Explained:
First Confirmed - First DTC to be confirmed (logged persistently) First Failed - First DTC to fail (may not be confirmed yet) Recent Confirmed - Most recent confirmed DTC Recent Failed - Most recent failed DTC

Note: DTC codes shown are in ISO format (raw decimal values). These codes may need to be converted to standard OBD-II format (P0XXX, P2XXX, etc.) for lookup. ℹ️ Pending Codes - Monitor for potential issues, but not yet confirmed.