Open Issue: Diagnosis Of Open And Short Circuit Faults With Freeze Frame Data For OBD-I Grade A Proposal By India

Background EPPR Slide 5, India proposal to delete Need for FFD for Grade A. EPPR Japan Proposal slide 7 on FFD requirement for Grade A Discussion during EPPR 15 on this point and need for more data from India.

Data generation Based on the request at EPPR 15, India collected data on two vehicles. Both vehicles had Engine Controller (ECU) from different manufacturer Both ECU’s are compliant to OBD I fully Faults were created in both vehicles in different sensors at two different operating points

ECU Freeze Frame data ECU Freeze Frame data captured during open and short circuit faults of sensors like Engine temperature sensor, Throttle Position Sensor and Lambda sensor for ECUs from two different manufacturers Freeze frame data also captured at different engine speeds to identify the possible link between Freeze Frame data and the root cause of faults.

Manufacturer 1 ECU Freeze Frame Data Engine Temperature Sensor short

Manufacturer 1 ECU Freeze Frame Data

Engine Temperature Sensor open Manufacturer 1 ECU Freeze Frame Data

Engine Temperature Sensor open Manufacturer 1 ECU Freeze Frame Data

O2 Sensor open Manufacturer 1 ECU Freeze Frame Data

O2 Sensor open Manufacturer 1 ECU Freeze Frame Data

O2 Sensor heater short Manufacturer 1 ECU Freeze Frame Data

O2 Sensor heater short Manufacturer 1 ECU Freeze Frame Data

TPS Open Manufacturer 1 ECU Freeze Frame Data

TPS Open Manufacturer 1 ECU Freeze Frame Data

TPS Short Manufacturer 1 ECU Freeze Frame Data

TPS Short Manufacturer 1 ECU Freeze Frame Data

Injector Open Manufacturer 1 ECU Freeze Frame Data

Injector Open Manufacturer 1 ECU Freeze Frame Data

Injector Short Manufacturer 1 ECU Freeze Frame Data

Injector Short Manufacturer 1 ECU Freeze Frame Data

Manufacturer 2 ECU Freeze Frame Data Engine Temperature Sensor short

Engine Temperature Sensor open Manufacturer 2 ECU Freeze Frame Data

Engine Temperature Sensor open Manufacturer 2 ECU Freeze Frame Data

TPS Open Manufacturer 2 ECU Freeze Frame Data

TPS Open Manufacturer 2 ECU Freeze Frame Data

TPS Short Manufacturer 2 ECU Freeze Frame Data

Injector Open Manufacturer 2 ECU Freeze Frame Data

Injector Short Manufacturer 2 ECU Freeze Frame Data

Conclusions Freeze frame data captured during open and short circuit faults of sensors at different engine speeds does not have sufficient information to identify cause for fault Freeze frame data will not help in failure cause analysis for open and short circuit faults Hence freeze frame data need not be mandatory for OBD I Grade A