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Subaru Impreza 3 / Impreza WRX / Impreza WRX STI. Manual - part 336

GD(H4DOTC)-96

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

Measure reaction time (t1, t2, t3) and reaction time (t4, t5, t6). Use the average value of the reaction time to

obtain the diagnostic value.

• Abnormality Judgment
Judge as NG when the following conditions are established.

Time Needed for Diagnosis: 1000 ms × [1 time(s)/2] + 1000 ms × 3 time(s) + 500 ms

Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-

cles.
• Normality Judgment
Judge as OK and clear the NG if the following conditions are established.

Time Needed for Diagnosis: 1000 ms × [1 time(s)/2] + 1000 ms × 3 time(s) + 500 ms

Judgment Value

Malfunction Criteria

Threshold Value

DTC

(t1 + t2 + t3)/3

> 420 ms (Models without SI-DRIVE)
> 380 ms (Models with SI-DRIVE)

P015A and P015B

and

(t4 + t5 + t6)/3

> 420 ms (Models without SI-DRIVE)
> 380 ms (Models with SI-DRIVE)

Judgment Value

Malfunction Criteria

Threshold Value

DTC

(t1 + t2 + t3)/3

≤ 420 ms (Models without SI-DRIVE)

≤ 380 ms (Models with SI-DRIVE)

P015A and P015B

(t4 + t5 + t6)/3

≤ 420 ms (Models without SI-DRIVE)

≤ 380 ms (Models with SI-DRIVE)

EN-09891

Time

Lean

Rich

Lean

Rich

STFT

Time

Sensor output

GD(H4DOTC)-97

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

AZ:DTC P015B O2 SENSOR DELAYED RESPONSE - LEAN TO RICH (BANK 1

SENSOR 1)

1. OUTLINE OF DIAGNOSIS

NOTE:

For the detection standard, refer to DTC P015A. <Ref. to GD(H4DOTC)-91, DTC P015A O2 SENSOR DE-

LAYED RESPONSE - RICH TO LEAN (BANK 1 SENSOR 1), Diagnostic Trouble Code (DTC) Detecting Cri-

teria.>

GD(H4DOTC)-98

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

BA:DTC P0171 SYSTEM TOO LEAN (BANK 1)

1. OUTLINE OF DIAGNOSIS

Detect fuel system malfunction by the amount of main feedback control.
Diagnostic method
Fuel system is diagnosed by comparing the target air fuel ratio calculated by ECM with the actual air fuel ratio

measured by sensor.

2. ENABLE CONDITIONS

3. GENERAL DRIVING CYCLE

Perform the diagnosis continuously at idling or at a constant speed after warming up the engine.

4. DIAGNOSTIC METHOD

• Abnormality Judgment
Compare the diagnostic value (fsobd) with the threshold value, and if a condition meeting the malfunction cri-

teria below continues for 10 s × 3 time(s) or more, judge that there is a fault in the fuel system.

Time Needed for Diagnosis: 10 s × 3 time(s)

Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-

cles.
• Normality Judgment
Judge as OK and clear the NG if the continuous time while the following conditions are established is more

than the predetermined time.

Time Needed for Diagnosis: 10 s

Secondary Parameters

Enable Conditions

A/F main learning system

In operation

Engine load change

< 0.02 g/rev (0 oz/rev)

Engine load

≥ Value of Map 1

Map 1

Engine speed (rpm)

Idling

650

1000

1500

2000

2500

3000

3500

4000

4500

Measured value (g (oz)/rev)

0 (0)

Judgment Value

Malfunction Criteria

Threshold Value

fsobd = (sglmd – tglmda) + faf + flaf

≥ Value from Map 2

In this case: sglmd = measured lambda

tglmda = target lambda

faf = main feedback compensation coefficient (every 64 milliseconds)
flaf = main feedback learning compensation coefficient

Map 2

Amount of air (g (oz)/s)

0 (0)

3.2

(0.11)

6.4

(0.23)

9.6

(0.34)

12.8

(0.45)

(0.56)

19.2

(0.68)

fsobdL1 (%)

1.35

Judgment Value

Malfunction Criteria

Threshold Value

fsobd = (sglmd – tglmda) + faf + flaf

< 1.15

GD(H4DOTC)-99

Diagnostic Trouble Code (DTC) Detecting Criteria

GENERAL DESCRIPTION

BB:DTC P0172 SYSTEM TOO RICH (BANK 1)

1. OUTLINE OF DIAGNOSIS

measured by sensor.

2. ENABLE CONDITIONS

3. GENERAL DRIVING CYCLE

Perform the diagnosis continuously at idling or at a constant speed after warming up the engine.

4. DIAGNOSTIC METHOD

• Abnormality Judgment
Compare the diagnostic value (fsobd) with the threshold value, and if a condition meeting the malfunction cri-

teria below continues for 10 s × 3 time(s) or more, judge that there is a fault in the fuel system.

Time Needed for Diagnosis: 10 s × 3 time(s)

Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cy-

cles.
• Normality Judgment
Judge as OK if the status that the criteria below are met continues for 10 seconds.

Time Needed for Diagnosis: 10 s

Secondary Parameters

Enable Conditions

A/F main learning system

In operation

Engine load change

≤ 0.02 g/rev (0 oz/rev)

Learning value of EVAP conc.

< 1

Cumulative time of canister purge after engine start

≥ 0 s

Continuous period after canister purge starting

≥ 0 ms

Engine load

≥ Value of Map 1

Map 1

Engine speed (rpm)

Idling

650

1000

1500

2000

2500

3000

3500

4000

4500

Measured value (g (oz)/rev)

0 (0)

Judgment Value

Malfunction Criteria

Threshold Value

fsobd = (sglmd – tglmda) + faf + flaf

< Value of Map 2

In this case: sglmd = measured lambda

tglmda = target lambda

faf = main feedback compensation coefficient (every 64 milliseconds)
flaf = main feedback learning compensation coefficient

Map 2

Amount of air (g (oz)/s)

0 (0)

3.2

(0.11)

6.4

(0.23)

9.6

(0.34)

12.8

(0.45)

(0.56)

19.2

(0.68)

fsobdL1 (%)

0.65

Judgment Value

Malfunction Criteria

Threshold Value

fsobd = (sglmd – tglmda) + faf + flaf

≥ 0.85

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