Honda HR-V: PGM-FI System Description - On-board Snapshot

Overview

For an easy analysis of problems caused by engine stalls and starting problems, the powertrain control module (PCM) uses an on-board snapshot to record the operational conditions at the time of occurrence of engine stalls and engine starting problems.

There are three types of on-board snapshots: the on-board snapshot when DTC is stored, the on-board snapshot when engine stalls, and the on-board snapshot when engine does not start.

The data of the on-board snapshots memorized by the PCM can be checked with the HDS.

Make sure to clear each type of on-board snapshots after checking it. PCM only memorizes their on-board snapshots when they are initially triggered.

Control

On-board snapshot when engine stalls:

The preconditions for recording an on-board snapshot when the engine stalls are shown below. When an engine stall occurs under these preconditions, the parameters related to the engine stall are stored in the PCM - for a time span extending for nine seconds before the engine stall and one second after the engine stall - covering a total of 10 seconds.

The precondition is:

• After 5 seconds have elapsed after engine start (engine speed is 500 rpm or higher) (In case of an engine stall within 5 seconds after the engine started, this is memorized on the side of the on-board snapshot when engine does not start (engine starts but stalls immediately)
• Engine speed at the time of an engine stall below 3, 000 rpm
• After expiration of 1 drive cycle, after PCM reset, or 12 volt battery terminal disconnection.
• Not during SCS short

*: In case of an engine stall for a vehicle with manual transmission at a vehicle speed of 3.1 mph (5 km/h) or lower, the on-board snapshot is not memorized.

On-board snapshot when engine does not start:

The three types 'engine is hard to start', 'engine will not start', and 'engine start but stalls immediately' are set for an on-board snapshot at the time of engine starting problems.

The preconditions for recording an on-board snapshot when engine does not start are as shown below, and when engine starting problems occur under these preconditions, the parameters related to the engine starting problems are memorized in the PCM.

The precondition is:

• After expiration of 1 drive cycle after PCM reset or 12 volt battery terminal disconnection.
• Not during SCS short

Timer for the evaluation of starting problems:

The timer for evaluation of engine starting problems is variable, and it depends on the engine coolant temperature when the engine starts, the relation between the engine coolant temperature and the engine start time is as shown below.

On-board snapshot of "engine is hard to start" and "engine will not start":

An on-board snapshot is taken when an engine does not start or when an engine is hard to start. The snapshot is taken when cranking (engine speed 500 rpm or lower) takes longer than the specified time (timer for the evaluation of starting problems: variable according to the conditions at the time of start). If it is determined that a starting problem exists, the parameters related to the starting problem (for nine seconds before the evaluation of the starting problem and one second after the evaluation of starting problem) are stored in the PCM, covering a total of 10 seconds.

On-board snapshot of "engine starts but stalls immediately":

An on-board snapshot is taken when an engine stall occurs within 5 seconds after the engine start, although the engine started (engine speed 500 rpm or higher) with cranking (engine speed 500 rpm or lower) within the specified time (timer for evaluation of starting problems: variable according to the conditions at the time of start). The parameters related to the stall after a complete combustion process for the 9 seconds before the engine stall and one second after the engine stall are stored in the PCM, covering a total of 10 seconds.

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