1A-44 Engine Control System
ECM Voltage and Continuity Test/Measurement
To test and measure the ECM for voltage and
continuity, use a circuit breaker box and 4HL1 adapter
harness.
Functional Check List
Hearing Diagnostic
1. Using the Engine Control System Diagnostic
Chart, completely hear and comprehend the
customer complaint.
Reference:
Proceed the process by focusing on the possible
faulty system estimated from the fault (fact)
instead of random hearing.
2. Judge the failure information accurately.
Comprehend the situation concretely based on
5W1H principle.
Example: Low temperature, startup stage,
permanent generation, vicinity of engine, metallic
sound, etc.
Key points on hearing
LNW21ASH010501
1
17
34
51
85
68
102
119
130
18
35
52
69
86
103
120
A
B
C
V
Hearing
The objective is to comprehend the symptom completely based on the
customer complaint and provide accurate diagnostic.
On-Board Diagnostic System
Check
The objective is to identify the faulty portion on the electronic engine control
system. (Checking procedure)
Inactive CHECK ENGINE Lamp
(MIL) Check
The objective is to check the CHECK ENGINE lamp (MIL) when it is not
turned on even after starter switch turn-on.
Active CHECK ENGINE Lamp
(MIL) Check
The objective is to check the CHECK ENGINE lamp (MIL) when it does not
blink (i.e., it keeps continuous lighting) even after diagnostic switch turn-on.
ECM Power Supply and
Grounding System Circuit Check
The objective is to check ECM power supply and grounding system circuits
when they seem to be faulty.
• What
• Faulty event
• When
• Date and time, generation
frequency
• Where
• Situation of road
• State
• Running condition, driving
condition, weather conditions
• Result
• Feeling of fault
