LEMON Manuals: Even more car manuals for everyone
Home >> Subaru >> 2021 >> Ascent Base >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control System (Diagnostics) (3 Of 4) >> Diagnostic Procedure with Diagnostic Trouble Code (DTC) >> DTC P1378: Pre-Ignition Detected >> General Description >> Diagnostic Method

Diagnostic Method

Judge as NG when the following conditions are established.

Judgment value 

PRE-IGNITION DETECTION CONTROL

Malfunction Criteria Threshold Value
Delay value from the before top dead 0.277 or more
center 70 deg until the pre-ignition analysis starts  
and  
Delay value from the ignition timing until the pre-ignition analysis ends
and		 Value of Map 1 or less
Analyzed pressure change value Value of Map 2 or more
MAP SPECIFICATION (1)

Diagnostic value Crankshaft angle (deg)
50 60 70 80 90 100 110 120
Engine speed (rpm) 800 16.9 18.05 19.2 20.35 21.5 21.64 21.64 21.64
1200 15.89 17.04 18.19 19.34 20.49 21.64 21.64 21.64
1600 19.48 19.48 19.48 19.48 19.48 19.48 20.104 20.728
2000 20.44 20.44 20.44 20.44 20.44 20.44 20.44 20.44
2400 20.7 21.2 21.2 21.2 21.2 21.2 21.2 21.2
2800 20.8 21.1 21.1 21.6 21.6 22.12 22.12 22.12
3200 20.8 21.3 21.8 22.3 22.5 22.5 23.03 23.03
3600 20.8 21.3 21.8 22.3 22.8 22.8 23.51 23.51
4000 20.8 21.3 21.8 22.3 22.84 22.84 22.84 22.84
4400 18.4 19.4 20.4 21.4 22.4 23.4 24.57 24.57
4800 18.4 19.4 20.4 21.4 22.4 24.95 24.95 24.95
5200 18.4 19.4 20.4 21.4 22.4 24.33 24.33 24.33
5600 18.4 19.4 20.4 21.4 22.4 22.55 22.55 22.55
6000 18.4 19.4 20.4 21.4 22.4 22.55 22.55 22.55
6400 18.4 19.4 20.4 21.4 22.4 22.55 22.55 22.55
6800 18.4 19.4 20.4 21.4 22.4 22.55 22.55 22.55
Diagnostic value Crankshaft angle (deg)
130 140 150 160 170 180 190 200
Engine speed (rpm) 800 21.64 21.64 21.64 21.64 21.64 21.64 21.64 21.64
1200 21.64 21.64 21.64 21.64 21.64 21.64 21.64 21.64
1600 20.728 20.728 20.728 20.728 20.728 20.728 20.728 20.728
2000 20.44 20.44 20.44 20.44 20.44 20.44 20.44 20.44
2400 20.77 20.34 20.2 20.06 20.06 20.06 20.06 20.06
2800 21.83 21.54 21.54 21.54 21.54 21.54 21.54 21.54
3200 22.985 22.94 22.795 22.65 22.455 22.26 22.065 21.87
3600 23.51 23.51 23.51 23.51 22.79 22.07 22.07 22.07
4000 22.84 22.84 22.84 22.84 22.84 22.84 22.84 22.84
4400 24.57 24.57 24.28 23.99 22.935 21.88 21.88 21.88
4800 24.665 24.38 24.38 24.38 23.59 22.8 22.8 22.8
5200 24.565 24.8 24.8 24.8 24.39 23.2 23.2 23.2
5600 23.225 23.9 23.9 23.9 23.2 22.5 22.5 22.5
6000 23.225 23.9 23.9 23.9 23.2 22.5 22.5 22.5
6400 23.225 23.9 23.9 23.9 23.2 22.5 22.5 22.5
6800 23.225 23.9 23.9 23.9 23.2 22.5 22.5 22.5
MAP SPECIFICATION (2)

Diagnostic value Crankshaft angle (deg)
90 100 110 120 130 140 160 180
Engine speed (rpm) 800 10000 2000 2000 2000 2000 2000 2000 2000
1200 10000 2000 2000 2000 2000 2000 2000 2000
1600 10000 2000 2000 2000 2000 2000 2000 2000
2000 10000 2000 2000 2000 2000 2000 2000 2000
2400 10000 2000 2000 2000 2000 2000 2000 2000
2800 10000 2000 2000 2000 2000 2300 2300 2300
3200 10000 2000 2000 2000 3100 2500 2500 2500
3600 10000 2500 2500 2500 3200 2800 2800 2800
4000 10000 2800 2800 3200 4500 3500 3500 3500
4400 10000 4000 4000 4400 5600 4400 4400 4400
4800 10000 4600 4600 4600 5300 4400 4400 4400
5200 10000 4700 4700 4700 7200 5500 5500 5500
5600 10000 5600 5600 5600 8500 6400 6400 6400
6000 10000 6600 6600 6600 10000 7300 7300 7300
6400 10000 7700 7700 7700 10000 8200 8200 8200
6800 10000 10000 10000 10000 10000 10000 10000 10000
CONTROL WITH NON-STANDARD FUEL SUPPLIED

Malfunction Criteria Threshold Value
Knocking compensation (DKNK) and -12 deg or less
186 times or more
Accumulation value of number of knocking cylinder  
Knocking compensation (PCMP) and -9.8 deg or less
186 times or more
Accumulation value of number of knocking cylinder  

Time needed for diagnosis:  Less than 1 s

Malfunction indicator light illumination:  Does not illuminate.

scientia non olet · About LEMON Manuals