Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

Ignition Control Module: Testing and Inspection





IGNITION COIL AND IGNITION POWER TRANSISTOR
- Ignition coil primary signal Refer to Ignition System
- Ignition power transistor control signal

Measurement Method
1. Disconnect the distributor (ignition power transistor) connector, and connect the special tool (test harness: MB991348) in between. (All terminals should be connected.)
2. Connect the analyzer special patterns pickup to distributor connector terminal 3.

Alternate method (Test harness not available)
1. Connect the analyzer special patterns pickup to PCM terminal 11.











Wave Pattern Observation Points
Point: Condition of wave pattern build-up section and maximum voltage (Refer to abnormal wave pattern examples 1 and 2.)

Examples of Abnormal Wave Patterns




- Example 1
Wave pattern during engine cranking

CAUSE OF PROBLEM
Open-circuit in ignition primary circuit

WAVE PATTERN CHARACTERISTICS
Top-right part of the build-up section cannot be seen, and voltage value is approximately 2V too low.




- Example 2
Wave pattern during engine cranking

CAUSE OF PROBLEM
Malfunction in ignition power transistor

WAVE PATTERN CHARACTERISTICS
Power voltage results when the ignition power transistor is ON.