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Maintenance alert detection - Guidance for Connected Mobility on AWS
Vehicle type detectionICE vehicle alertsEV vehicle alertsCommon alerts (ICE and EV)Processing flowMaintenance alert DynamoDB record

Maintenance alert detection

The MaintenanceProcessor consumes from the cms-telemetry-maintenance Kafka topic and analyzes vehicle health signals to detect conditions that require maintenance attention.

Vehicle type detection

The processor automatically detects whether a vehicle is ICE (Internal Combustion Engine) or EV (Electric Vehicle) based on the telemetry signals present:

  • EV detected — If soc (state of charge) > 0, or volt (HV battery voltage) > 0, or regen_pwr (regenerative braking power) ≠ 0

  • ICE detected — If fuel_rate > 0 or oil_life > 0

A vehicle can be both (hybrid). The processor applies the appropriate maintenance rules based on the detected type.

ICE vehicle alerts

Alert Type Severity Condition DTC Code

OIL_CHANGE_OVERDUE

CRITICAL

oil_life < 10%

P0524

OIL_CHANGE_DUE

HIGH

oil_life < 25%

P0524

OIL_PRESSURE_LOW

CRITICAL

oilPressure < 15 PSI

P0520

OIL_PRESSURE_WARNING

HIGH

oilPressure < 25 PSI

P0520

ENGINE_OVERHEATING

CRITICAL

engineTemp > 230°F

P0217

ENGINE_RUNNING_HOT

HIGH

engineTemp > 210°F

P0217

COOLANT_OVERHEATING

CRITICAL

coolant_temp > 220°F

P0217

EV vehicle alerts

Alert Type Severity Condition

HV_BATTERY_VOLTAGE_LOW

CRITICAL

volt < 300V (battery pack failure risk)

HV_BATTERY_DEGRADATION

HIGH

volt < 320V (capacity loss)

HV_BATTERY_OVERVOLTAGE

CRITICAL

volt > 450V (charger malfunction)

BATTERY_CRITICALLY_LOW

CRITICAL

soc < 5%

BATTERY_LOW_WARNING

HIGH

soc < 15%

BATTERY_CAPACITY_DEGRADATION

MEDIUM

soc > 95% AND volt < 380V (full charge voltage low)

REGEN_BRAKING_EXCESSIVE

MEDIUM

regen_pwr < -50 kW

BATTERY_COOLING_OVERTEMP

HIGH

coolant_temp > 60°F (thermal management failure)

MOTOR_OVERHEATING

CRITICAL

engineTemp > 150°F (motor protection required)

MOTOR_RUNNING_HOT

HIGH

engineTemp > 130°F

CHARGING_SYSTEM_OVERVOLTAGE

HIGH

batteryVoltage > 15V (12V system)

Common alerts (ICE and EV)

Alert Type Severity Condition

BRAKE_REPLACEMENT_CRITICAL

CRITICAL

brake_wear < 20% (ICE) or < 15% (EV)

BRAKE_REPLACEMENT_DUE

HIGH

brake_wear < 35% (ICE) or < 30% (EV)

TIRE_REPLACEMENT_CRITICAL

CRITICAL

any tire tread < 2.0mm

TIRE_REPLACEMENT_DUE

HIGH

any tire tread < 4.0mm

FILTER_REPLACEMENT

HIGH

filter_life < 15%

LOW_BATTERY_12V

CRITICAL

batteryVoltage < 11.5V

DTC_ACTIVE

HIGH

dtc_codes_active = 1

Note: EV vehicles have higher brake wear thresholds because regenerative braking reduces mechanical brake usage.

Processing flow

For each telemetry message:

  1. Parse the JSON and extract all maintenance-critical signal values.

  2. Detect vehicle type (ICE, EV, or hybrid) from the signals present.

  3. Apply the appropriate maintenance rules based on vehicle type.

  4. For each triggered alert, check deduplication: has this alert type already been generated for this message hash?

  5. Write each new alert to the cms-{stage}-storage-maintenance-alerts DynamoDB table.

Maintenance alert DynamoDB record

{
  "alertId": "MA-e5f6g7h8",
  "vehicleId": "VEH-0049",
  "tripId": "VEH-0049-1709751600000-fc9567",
  "alertType": "ENGINE_OVERHEATING",
  "severity": "CRITICAL",
  "timestamp": 1709753400000,
  "message": "Engine overheating: 235°F - cooling system failure",
  "triggerSignal": "engineTemp",
  "triggerValue": 235.0,
  "threshold": 230.0,
  "dtcCode": "P0217",
  "vehicleType": "ICE",
  "rule": "engineTemp > 230°F"
}