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Intake Manifold Air Temperature Sensor Circuit
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Overview
| CODE | REASON | EFFECT |
| Fault Code: 153 PID: P105 SPN: 105 FMI: 3 LAMP: Yellow SRT: 00-090 |
High voltage detected at the intake manifold air temperature signal pin 25 of the sensor harness connector. | Fan will stay on if controlled by the electronic control module (ECM). No engine protection for intake manifold air temperature. |
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Intake Manifold Air Temperature Sensor Circuit |
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Circuit Description
The intake manifold air temperature sensor is used by the ECM to monitor the temperature of the engine intake air. The intake manifold air temperature signal is used by the ECM for the engine protection system and timing and fueling control.
Component Location
- M11 – The intake manifold air temperature sensor is located on the top rear half of the intake manifold.
- N14 – The intake manifold air temperature sensor is located on the side of the intake manifold just above the ECM.
Shop Talk
The resistance of the sensor varies with the temperature. Compare the reading with this table.
| Temperature (°C) | Temperature [°F] | Resistance (ohms) |
| 0 | 32 | 30k to 36k |
| 25 | 77 | 9k to 11k |
| 50 | 122 | 3k to 4k |
| 75 | 167 | 1350 to 1500 |
| 100 | 212 | 600 to 675 |
Cautions and Warnings
 CAUTION
To reduce the possibility of pin and harness damage, use the following test leads when taking a measurement: |
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CAUTION
To reduce the possibility of damaging a new ECM, all other active fault codes must be investigated prior to replacing the ECM. |
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CAUTION
To reduce the possibility of pin and harness damage, use the following test lead when taking a measurement: |
|
CAUTION
To reduce the possibility of pin and harness damage, use the following test lead when taking a measurement: |
|
CAUTION
To reduce the possibility of pin and harness damage, use the following test lead when taking a measurement: |
Troubleshooting Steps
| STEPS | SPECIFICATIONS | |
|---|---|---|
| STEP 1. | Check the intake manifold air temperature sensor. | |
| STEP 1A. Inspect the intake manifold air temperature sensor and the sensor harness connector pins. | No damaged pins | |
| STEP 1B. Read the fault codes. | Fault Code 153 active | |
| STEP 1C. Check the resistance of the intake manifold air temperature sensor. | 175 ohms to 244k ohms | |
| STEP 2. | Check the sensor harness. | |
| STEP 2A. Inspect the sensor harness and the ECM connector pins. | No damaged pins | |
| STEP 2B. Read the fault codes. | Fault Code 153 active | |
| STEP 2C. Check for a short circuit from pin to pin. | More than 100k ohms | |
| STEP 3. | Check for the ECM response. | |
| STEP 3A. Check for the appropriate ECM response. | Fault Code 153 inactive, Fault Code 154 active | |
| STEP 3B. Check the signal pin resistance at the ECM. | Less than 100k ohms | |
| STEP 4. | Clear the fault codes. | |
| STEP 4A. Disable the fault code. | Fault Code 153 inactive | |
| STEP 4B. Clear the inactive fault codes. | All fault codes cleared | |
Guided Step 1 – Check the intake manifold air temperature sensor.
| Guided Step 1A – Inspect the intake manifold air temperature sensor and the sensor harness connector pins. | |
|---|---|
Conditions
Action
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| OK | NOT OK |
| No damaged pins | Repair the damaged pins.
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| Guided Step 1B – Read the fault codes. | |
|---|---|
Conditions
Action
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| OK | NOT OK |
| Fault Code 153 active | Repair complete. |
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CAUTION
To reduce the possibility of pin and harness damage, use the following test lead when taking a measurement: |
| Guided Step 1C – Check the resistance of the intake manifold air temperature sensor. | ||
|---|---|---|
Conditions
Action
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| OK | NOT OK | |
| 175 ohms to 244k ohms | Replace the intake manifold air temperature sensor. Refer to Procedure 019-059. | |
Guided Step 2 – Check the sensor harness.
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CAUTION
To reduce the possibility of damaging a new ECM, all other active fault codes must be investigated prior to replacing the ECM. |
| Guided Step 2A – Inspect the sensor harness and the ECM connector pins. | |
|---|---|
Conditions
Action
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| OK | NOT OK |
| No damaged pins | Repair the damaged pins.
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| Guided Step 2B – Read the fault codes. | |
|---|---|
Conditions
Action
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| OK | NOT OK |
| Fault Code 153 active | Repair complete. |
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CAUTION
To reduce the possibility of pin and harness damage, use the following test lead when taking a measurement: |
| Guided Step 2C – Check for a short circuit from pin to pin. | ||
|---|---|---|
Conditions
Action
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| OK | NOT OK | |
| More than 100k ohms | Repair or replace the sensor harness. | |
Guided Step 3 – Check for the ECM response.
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CAUTION
To reduce the possibility of pin and harness damage, use the following test lead when taking a measurement: |
| Guided Step 3A – Check for the appropriate ECM response. | ||
|---|---|---|
Conditions
Action
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| OK | NOT OK | |
| Fault Code 153 inactive Fault Code 154 active |
Replace the ECM. Refer to Procedure 019-031. | |
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CAUTION
To reduce the possibility of pin and harness damage, use the following test lead when taking a measurement: |
| Guided Step 3B – Check signal pin resistance at the ECM. | |
|---|---|
Conditions
Action
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| OK | NOT OK |
| Less than 100k ohms | Replace the ECM. Refer to Procedure 019-031. |
Guided Step 4 – Clear the fault codes.
| Guided Step 4A – Disable the fault code. | |
|---|---|
Conditions
Action
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| OK | NOT OK |
| Fault Code 153 inactive | Return to the troubleshooting steps or contact your nearest Cummins Authorized Repair Location if all steps have been completed and checked again. |
| Guided Step 4B – Clear the inactive fault codes. | |
|---|---|
Conditions
Action
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| OK | NOT OK |
| All fault codes cleared | Troubleshoot any remaining active fault codes. |
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Repair complete
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Appropriate troubleshooting chart
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