MBE 900 4000 Troubleshooting – Section 10.2 Troubleshooting PID 105

Section 10.2
Troubleshooting PID 105

The following procedures will troubleshoot PID 105.‪

Section 10.2.1
105 03 – Intake Air Temperature Sensor Open Circuit

Perform the following steps to troubleshoot an IAT sensor open circuit fault:‪

1. With boost air combination sensor connected, check for additional active fault codes. See Figure "Turbo Boost Air Combination Sensor" .
   1. If fault code 102 03 is active in addition to 105 03, repair open circuit in 55-pin connector wire 21 (on MBE 900 — see Figure "Turbo Boost Air Combination Sensor Wiring for MBE 900 Engine" ) or wire 29 (on MBE 4000 — see Figure "Turbo Boost Air Combination Sensor Wiring for MBE 4000 Engine" ) to pin 1 of the sensor. Erase fault code memory.
      

      Figure 1. Turbo Boost Air Combination Sensor Wiring for MBE 900 Engine

      

      Figure 2. Turbo Boost Air Combination Sensor Wiring for MBE 4000 Engine

   2. If fault code 110 03 is active in addition to 105 03, go to step 2 .
   3. If only fault code 105 03 is active, go to step 3 .
2. Measure the voltage at pin 2 of the combination sensor. See Figure "Turbo Boost Air Combination Sensor" .
   1. If more than 10 V, repair short to vehicle system power in 55-pin connector wire 48 (on the MBE 900 — see Figure "Turbo Boost Air Combination Sensor Wiring for MBE 900 Engine" ) or wire 7 (on the MBE 4000 — see Figure "Turbo Boost Air Combination Sensor Wiring for MBE 4000 Engine" ) to pin 2 of the sensor. Erase fault code memory.
   2. If less than 10 V, go to step 5 .
3. Bridge pins 1 and 2 of the combination sensor. See Figure "Turbo Boost Air Combination Sensor" .
   1. If new fault code 105 04 is not active, repair open circuit in 55-pin connector wire 48 (on the MBE 900 — see Figure "Turbo Boost Air Combination Sensor Wiring for MBE 900 Engine" ) or wire 7 (on the MBE 4000 — see Figure "Turbo Boost Air Combination Sensor Wiring for MBE 4000 Engine" ) to pin 2 of the sensor. Erase fault code memory.
   2. If new fault code 105 04 is active, go to step 4 .
4. Bridge pins 1 and 2 of the combination sensor on the plug side. See Figure "Turbo Boost Air Combination Sensor" .
   1. If new fault 102 04 is not active, replace the combination sensor. Erase fault code memory.
   2. If new fault 102 04 is active, repair short to power in 55-pin connector wire 48 (on the MBE 900 — see Figure "Turbo Boost Air Combination Sensor Wiring for MBE 900 Engine" ) or wire 7 (on the MBE 4000 — see Figure "Turbo Boost Air Combination Sensor Wiring for MBE 4000 Engine" ) to pin 2 of the sensor. Erase fault code memory.
5. With combination sensor connected, measure the voltage at pin 1 of the sensor. See Figure "Turbo Boost Air Combination Sensor" .
   1. If less than 4.5 V, inspect and repair or replace all plug connectors, as required. Erase fault code memory.
   2. If more than 4.5 V, repair short to vehicle system power in 55-pin connector wire 34 to pin 1 of the Engine Coolant Temperature sensor. See Figure "Engine Coolant Temperature Sensor Wiring" . Erase fault code memory.
      

      Figure 3. Engine Coolant Temperature Sensor Wiring

Section 10.2.2
105 04 – Intake Air Temperature Sensor Short to Ground

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

1. Unplug the boost air combination sensor and check for additional fault codes.
   1. If new fault code 105 03 is active in addition to code 105 04, replace the sensor. Erase fault code memory.
   2. If new fault code 105 03 is not active, go to step 2 .
2. Measure the resistance between pin 2 of the combination sensor and vehicle ground. See Figure "Turbo Boost Air Combination Sensor" .
   1. If resistance is less than 30 kΩ, repair short to ground in 55-pin connector wire 48 (on the MBE 900 — see Figure "Turbo Boost Air Combination Sensor Wiring for MBE 900 Engine" ) or wire 7 (on the MBE 4000 — see Figure "Turbo Boost Air Combination Sensor Wiring for MBE 4000 Engine" ) to pin 2 of the sensor. Erase fault code memory.
   2. If resistance is greater than 30 kΩ, go to step 3 .
3. Check and clean the sensor contacts (remove any corrosion).
   1. If fault 105 04 is still active after checking and cleaning, replace the PLD-MR. Erase fault code memory.
   2. If fault 105 04 is not active after checking and cleaning, erase fault code memory.