MBE 900 DDEC VI Troubleshooting – Section 93.3 SPN 1636/FMI 4

Section 93.3
SPN 1636/FMI 4

A typical diagnosis is Intake Manifold Pressure/Temp Sensor Open Short to Ground.‪

Section 93.3.1
Intake Manifold Pressure/Temp Sensor Open or Short to Ground Check

Check as follows:‪

1. Check for multiple codes.
   1. If fault code 1636/4 and 3563 are both active, repair the open between pin 58 of the 120–pin MCM connector and pin 2 of the Intake Manifold Pressure/Temp Sensor. Refer to "93.3.1.1 Verify Repairs" .
   2. If only 1636/4 is active, go to step 2
      .
2. Disconnect the Intake Manifold Pressure/Temp Sensor.
3. Measure the resistance between pins 3 and 4 of the Intake Manifold Pressure/Temp Sensor.
   1. If resistance is greater than 130k Ω, replace the sensor. Refer to "93.3.1.1 Verify Repairs" .
   2. If resistance is less than 130k Ω, go to step 5 .
4. Turn the ignition ON (key ON, engine OFF).
5. Measure the voltage between pin 3 of the Intake Manifold Pressure/Temp Sensor and ground.
   1. If the voltage is greater than 2.75 volts, go to step 6 .
   2. If the voltage is less than 2.75 volts, repair the open between pin 3 of the Intake Manifold Pressure/Temp Sensor and pin 106 of the 120–pin MCM connector. See Figure "Intake Manifold Pressure/Temp Sensor Wiring" . Refer to "93.3.1.1 Verify Repairs" .
   

   Figure 1. Intake Manifold Pressure/Temp Sensor Wiring

6. Turn the ignition OFF.
7. Disconnect the 120–pin MCM connector.
8. Measure the resistance between pins 3 and 4 of the Intake Manifold Pressure/Temp Sensor harness connector.
   1. If resistance is greater than 5 Ω, repair the short to power on the circuit between pin 106 of the 120–pin MCM connector and pin 3 of the Intake Manifold Pressure/Temp Sensor harness connector. Refer to "93.3.1.1 Verify Repairs" .
   2. If resistance is less than 5 Ω, repair the short between wires 52 and `106 of the 120–pin MCM connector. Refer to "93.3.1.1 Verify Repairs" .

Section 93.3.1.1
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.