MBE 4000 DDEC VI Troubleshooting – Section 92.2 SPN 1636/FMI 3

Section 92.2
SPN 1636/FMI 3

The diagnostic condition is typically Intake Air Temperature Sensor Circuit failed high. The following procedures will troubleshoot SPN 1636/3.‪

Section 92.2.1
Circuit Failed High Check

Perform the following steps to troubleshoot a circuit failed high fault:‪

1. Disconnect the Intake Air Temperature Sensor.
2. Turn the Ignition ON.
   

   Figure 1. Intake Air Temperature Sensor

3. Measure the voltage between pins 1 and 2 of the Intake Air Temperature Sensor harness connector.
   1. If the voltage is greater than 2.75v, replace the Intake Air Temperature Sensor.
   2. If the voltage is less than 2.75v, go to step 4 .
4. Measure the voltage between pin 2 of the Intake Air Temperature Sensor harness connector and ground.
   1. If the voltage is greater than 2.75v, repair open between pin 1 of the Intake Air Temperature Sensor harness connector and pin 52 of the MCM 120-pin connector.
   2. If the voltage is less than 2.75v, repair open between pin 2 of the Intake Air Temperature Sensor harness connector and pin 106 of the MCM 120-pin connector.

Section 92.2.1.1
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.