This diagnostic condition is typically an open circuit.
44.2.1
Open Circuit Check
Check as follows:
1. Disconnect the Idle Validation Switch.
2. Turn the ignition ON (key ON, engine OFF).
3. Measure the voltage between the Idle Validation Switch pins 4 and 6.
[a] If the voltage is greater than 11.5 volts, go to step 7.
[b] If the voltage is less than 11.5 volts, go to step 4.
4. Measure the voltage between the Idle Validation Switch pin 4 and ground.
[a] If the voltage is greater than 11.5 volts, go to step 5.
[b] If the voltage is less than 11.5 volts, repair the open wire between pin 6 of the CPC
#1 connector and pin 4 of the Idle Validation Switch. Refer to section 44.2.1.1.
5. Disconnect the CPC #2 connector.
6. Measure the resistance between pin 2 of the CPC #2 connector and pin 6 of the Idle
Validation Switch.
[a] If the resistance is greater than 5Ω, repair the open the wire between pin 2 of the CPC
#2 connector and pin 6 of the Idle Validation Switch. Refer to section 44.2.1.1.
[b] If the resistance is less than 5Ω, replace the Idle Validation Switch. Refer to section
44.2.1.1.
7.Measure the voltage between the Idle Validation Switch pins 5 and 6.
[a] If the voltage is greater than 11.5 volts, replace the Idle Validation Switch.
Refer to section 44.2.1.1.
[b]If the voltage is less than 11.5 volts, repair the open the wire between pin 3 of the
CPC #1 connector and pin 5 of the Idle Validation Switch. Refer to section 44.2.1.1.
44.2.1.1
Verify Repairs
Verify repairs as follows:
1. Turn ignition OFF.
2. Reconnect any electrical connections that were disconnected to perform the diagnosis.
3. Clear codes with DDDL 7.0 or latest version.
4. Start and bring engine up to operating temperature (over 140°F/60°C).
5. Verify operation is satisfactory and no warning lamps illuminate. If warning lamps
illuminate, troubleshoot the codes. If assistance is required, call the Detroit Diesel
Customer Support Center at 313–592–5800.
