DTC P1378-00: Pre-ignition Detected [11/2019 - ]: Description

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If sudden early ignition (pre-ignition) occurs continuously in a short period of time, a DTC is stored. Pre-ignition is a phenomenon inherent to small displacement forced-induction engines. Atomized engine oil and detached deposits (carbon) can cause pre-ignition and promote engine knocking during low-speed, high-output operation. This is higher pressure knocking than normal knocking.

Pre-ignition is detected by the knock control sensor.

When pre-ignition occurs, the ECM limits output to suppress the pre-ignition. If pre-ignition occurs continuously, fuel cut may be performed in some situations, which may cause vehicle behavior similar to hesitation or shift shock. This is not a malfunction.

As pre-ignition cannot be detected if a knock control sensor malfunction occurs, the same fail-safe control occurs as for strong knock detection.

HINT:

When this DTC is stored, the ECM enters fail-safe mode.
During fail-safe mode, the ECM limits the output.
Fail-safe mode continues until a pass condition is detected.

DTC No.	Detection Item	DTC Detection Condition	MIL	Memory	Note
P1378-00	Pre-ignition Detected	Continuous pre-ignition prevention fuel-cut control is performed twice (1 trip detection logic). Continuous pre-ignition prevention fuel-cut control operation conditions: Sudden early ignition (pre-ignition) occurs 5 times or more continuously in a short period of time.	Does not come on	DTC stored	SAE Code: P1378

Trouble Area
Ignition system	Ignition malfunction of ignition coil assembly or spark plug
Fuel injection system	Decrease in fuel injection volume (for direct injection)
Lubrication system	High oil consumption Dilute / deteriorated oil Additive
Fuel system	Diesel fuel contamination Addition of fuel additives Fuel pump assembly Low quality fuel
Engine related	Accumulated deposit (in combustion chamber)
Intake system	Air leaks
Exhaust system	Clogged exhaust system component

HINT:

As strong knocking due to pre-ignition may be caused by multiple superimposed factors, it is important to comprehensively investigate all possible causes.
The risk of this occurring is increased if driving up a steep incline while towing in a low gear, as low-speed, high-output operation occurs.