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

Idle Speed/Throttle Actuator - Mechanical: Testing and Inspection

Code Chart C-15:




Throttle Opener VSV Wiring Circuit:






CIRCUIT DESCRIPTION:

The ECM uses the throttle opener control valve to hold the throttle open. This is to increase engine rpm during warm-up, and to obtain a normal operating temperature once the Coolant Temperature Sensor (CTS) senses the engine temperature is above 78°C (172°F).

TEST DESCRIPTION: The numbers below refer to circled numbers on the diagnostic chart.

1. Check that the control relay is supplying B+ to throttle opener valve.

2. This will determine if the problem is electrical or mechanical.

3. This checks the ECM for supplying a ground.