Series 60 DDEC VI Troubleshooting – Section 87.2 SPN 1636/FMI 4

Section 87.2
SPN 1636/FMI 4

A typical diagnosis is IAT Sensor Short to Ground.‪

Section 87.2.1
Intake Air Temperature Sensor Short to Ground Check

Perform the following steps to troubleshoot an IAT Sensor short to ground fault:‪

1. Disconnect the IAT Sensor.
2. Disconnect the 120–pin MCM connector.
3. Measure the resistance across pins 1 and 2 of the IAT Sensor connector.
   1. If the resistance is less than 5k Ω, repair the short between wires 52 and 106 of the 120–pin MCM Connector. Refer to "87.2.1.1 Verify Repairs" .
   2. If the resistance is greater than 5k Ω, go to step 4 .
4. Measure the resistance between pin 2 of the sensor harness connector and ground.
   1. If the resistance is less than 5 Ω, repair the short circuit between pin 2 of the sensor harness connector and ground. Refer to "87.2.1.1 Verify Repairs" .
   2. If the resistance is greater than 5 Ω, refer to "87.2.1.1 Verify Repairs" .

Section 87.2.1.1
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.