The typical diagnosis for this fault is circuit failed high.
24.2.1
High Voltage Check
Check as follows:
1. Disconnect the Accelerator Pedal (AP).
2. Turn ON the ignition (key ON, engine OFF).
3. Measure the voltage between pins B and C of the AP harness connector.
[a] If the voltage is between 4.5 and 5.5 volts, go to step 5.
[b] If the voltage is less than 4.5, go to step 4.
4. Measure the voltage between pins C of the AP harness connector and ground.
[a] If the voltage is between 4.5 and 5.5 volts, repair the open circuit between pin B of the
AP harness connector and pin 4 of the CPC #1 connector. Refer to section 24.2.1.1.
[b] If the voltage is less than 4.5, repair the open circuit between pin C of the AP harness
connector and pin 8 of the CPC #1 connector. Refer to section 24.2.1.1.
5. Turn OFF the ignition.
6. Disconnect the CPC #1 connector.
7.Measure the resistance between pin A of the AP harness connector and pin 7 of the CPC
#1 connector.
[a] If the resistance is greater than 3 Ω, repair the open circuit between pin A of the AP
harness connector and pin 7 of the CPC #1 connector. Refer to section 24.2.1.1.
[b] If the resistance is less than 3 Ω, replace the Accelerator Pedal. Refer to section 24.2.1.1.
24.2.1.1
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.
