Series 60 DDEC VI Troubleshooting – Section 24.1 SPN 91/FMI 2

Section 24.1
SPN 91/FMI 2

A typical diagnosis for the fault is erratic data.‪

Section 24.1.1
Erratic Data 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. See Figure "Accelerator Pedal Assembly Installation" .
   

   Figure 1. Accelerator Pedal Assembly Installation

   1. If the voltage is between 4.5 and 5.5 volts, go to step 5 .
   2. If the voltage is less than 4.5, go to step 4 .
4. Measure the voltage between pin C of the AP harness connector and ground.
   1. 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 "24.1.1.1 Verify Repairs" .
   2. 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 "24.1.1.1 Verify Repairs" .
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.
   1. 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 "24.1.1.1 Verify Repairs" .
   2. If the resistance is less than 3 Ω, replace the Accelerator Pedal. Refer to "24.1.1.1 Verify Repairs" .

Section 24.1.1.1
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.