Freeze Frame Data: Notes

ECM stores the engine and driving conditions (in the form of data as shown) at the moment of the detection of a malfunction in its memory. This data is called "Freeze frame data".

Therefore, it is possible to know engine and driving conditions (e.g., whether the engine was warm or not, where the vehicle was running or stopped, where air/fuel mixture was lean or rich) when a malfunction was detected by checking the freeze frame data. Also, ECM has a function to store each freeze frame data for three different malfunctions in the order as the malfunction is detected. Utilizing this function, it is possible to know the order of malfunctions that have been detected. Its use is helpful when rechecking or diagnosing a trouble.

For details of freeze frame data that can be read from ECM, refer to table below.

FREEZE FRAME DATA

DTC

Fuel System

Calculated Load

ECT

Short Term Fuel Trim

Long Term Fuel Trim

Engine Speed

Vehicle Speed

Ignition Advance

Intake Air Temperature

MAF

Absolute TP 1*

Evap Canist Prg Duty

Fuel Tank Level

Barometric Pres

Battery Voltage

Relative TP**

Absolute TP 2*

Absolute APP 1*

Absolute APP 2*

Target Throt Pos

NOTE:

For freeze flame data with asterisk (*), it indicates the ratio between power supply voltage and output voltage of related sensor.
When power supply voltage is 5.0 V and output voltage is 4.0 V, freeze frame data is displayed the following.
- For systems where the output is proportional to the input voltage, it displays 80% (= the percent of maximum input reference voltage).
- For systems where the output is inversely proportional to the input voltage, it displays 20% (=100% minus the percent of maximum input reference voltage).
For relative TP with asterisks (**) in above table, it indicates by formula ((output voltage - output voltage at closed throttle position)/power supply voltage).
When power supply voltage is 5.0 V and output voltage at closed throttle position is 1.0 V, freeze frame data is displayed the following.
- At closed throttle position (output voltage = 1.0 V), it displays 0%.
- At wide open throttle position (output voltage = 4.0 V), it displays 60%. However, for systems where the output is inversely proportional to the input voltage, it displays 100% minus above-mentioned formula.

Fig 1: Freeze Flame Data Reference Chart

Courtesy of SUZUKI OF AMERICA CORP.