P0545-EXHAUST GAS TEMPERATURE SENSOR CIRCUIT LOW - BANK 1 SENSOR 1
For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation
The Exhaust Gas Temperature Sensor 1/1 is located next to the O2 Sensor at the outlet of the Exhaust Manifold and is accessible from the top of the engine compartment. The Exhaust Gas Temperature Sensor 1/1 operates as a typical two wire 5-Volt sensor. It sends a signal to the Powertrain Control Module (PCM) indicating the temperature of the exhaust gases entering the Diesel Particualte Filter.
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When Monitored:
With the engine running.
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Set Condition:
The PCM detects that the (K384) Exhaust Gas Temperature Sensor 1/1 Signal circuit voltage is low for 0.5 second.
Possible Causes |
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| (K384) EXHAUST GAS TEMPERATURE SENSOR 1/1 SIGNAL CIRCUIT SHORTED TO GROUND |
| (K384) EXHAUST GAS TEMPERATURE SENSOR 1 SIGNAL CIRCUIT SHORTED TO THE (K385) SENSOR RETURN CIRCUIT |
| EXHAUST GAS TEMPERATURE SENSOR 1 |
| POWERTRAIN CONTROL MODULE (PCM) |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
| 1. | Ignition on, engine not running. |
| 2. | With the scan tool, select View DTCs. |
Is the status Active for this DTC?
Yes
- Go To 2
No
- Perform the INTERMITTENT DTC diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
2. CHECK THE EXHAUST GAS TEMPERATURE SENSOR 1/1
| 1. | Disconnect the Exhaust Gas Temperature Sensor 1/1 harness connector. |
| 2. | Turn the ignition on. |
| 3. | With the scan tool, select View DTCs. |
| 4. | Monitor the scan tool for at least two minutes. |
| NOTE: | The scan tool should display an Exhaust Gas Temperature Sensor 1/1 High DTC as active with the Exhaust Gas Temperature Sensor 1/1 connector unplugged. |
Does the scan tool display the DTC as described above?
Yes
- Replace the Exhaust Gas Temperature Sensor 1/1 in accordance with the service information.
- Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
- Go To 3
3. CHECK THE (K384) EXHAUST GAS TEMPERATURE SENSOR 1/1 SIGNAL CIRCUIT FOR A SHORT TO GROUND
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| 1. | Turn the ignition off. |
| 2. | Connect the PCM C1 harness connector. |
| 3. | Measure the resistance between ground and the (K384) Exhaust Gas Temperature Sensor 1/1 Signal circuit at the Exhaust Gas Temperature Sensor 1/1 harness connector. |
Is the resistance above 10k Ohms?
Yes
- Go To 4
No
- Repair the (K384) Exhaust Gas Temperature Sensor 1 Signal circuit for a short to ground.
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Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM)
- Standard Procedure).
4. CHECK FOR THE (K384) EXHAUST GAS TEMPERATURE SENSOR 1/1 SIGNAL CIRCUIT SHORTED TO THE (K385) SENSOR RETURN CIRCUIT
 |
| 1. | Measure the resistance between the (K384) Exhaust Gas Temperature Sensor 1 Signal circuit and the (K385) Sensor Return circuit at the Exhaust Gas Temperature Sensor 1/1 harness connector. |
Is the resistance above 10k Ohms?
Yes
- Go To 5
No
- Repair the (K384) Exhaust Gas Temperature Sensor 1/1 Signal circuit for a short to the (K385) Sensor Return circuit.
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Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM)
- Standard Procedure).
| 1. | Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Exhaust Gas Temperature Sensor 1/1 and the Powertrain Control Module (PCM). |
| 2. | Look for any chafed, pierced, pinched, or partially broken wires. |
| 3. | Look for broken, bent, pushed out or corroded terminals. |
| 4. | Perform any Technical Service Bulletins that may apply. |
Were any problems found?
Yes
- Repair as necessary.
- Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
- Replace the Powertrain Control Module (PCM) in accordance with the service information.
- Perform the PCM VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).