Oscilloscope Patterns and Waveforms

WAVE PATTERN INSPECTION USING AN ANALYZER




With Mitsubishi Test Harness
Disconnect the injector connector, and connect the special tool (test harness: MB991348) in between. (The power side and the engine control module side terminals should both be connected).

Alternative Method (when test harness is not available)
Alternative method (when test harness is not available) Connect the analyzer special patterns pickup to ECM terminals (51), (52), (60), (61), (105) and (109) for each of the six injectors.

Observation Conditions
Function - Special patterns
Pattern Height - Variable
Variable Pattern Selector - Display
Engine Rpm - Idling (700 rpm)

WAVE PATTERNS
Standard Wave Patterns






Observation Points:
Point A: Height of injector coil induced voltage
If the Injector coil induced voltage is low or doesn't appear at all, there is likely a short-circuit in the injector solenoid.

Point B: Injector drive time
The injector drive timing will be synchronized with the scan tool display (if a scan tool is used). When the engine is suddenly raced, the drive time trace will be greatly extended at first, but the drive time will soon match the engine speed.