Cummins 6.7-liter I6 engine has been a part of heavy-duty pickup trucks like Dodge Ram 2500/3500 since 2007. It has high power output and torque ratings suitable for high-end applications.
Moreover, these engines have several sensors to ensure peak performance with improved fuel economy and emission control to meet the regulations.
Mass air flow and intake air temperature sensors are located on the intake manifold of the Cummins 6.7L engine. NOx, O2, and differential pressure sensors are present on the exhaust manifold. You can find the crankshaft and camshaft position sensors on the left-hand side of the crank pulley beside each other. Furthermore, the EGR temperature sensor has a location on the crossover tube.
This article will guide you regarding the location of many sensors on the Cummins 6.7-liter I6 engine to ensure optimal performance.
We will also highlight the purpose of each sensor and possible causes for its malfunctioning to facilitate you during repair work.
Cummins’s 6.7-liter turbo diesel engine uses several sensors to measure its parameters, including temperature, pressure, fluid levels, position, and speed.
Here is a list of various sensors installed on the 6.7-liter engine and their location to facilitate you during repair work.
- 1 Mass airflow (MAF) sensor
- 2 Intake air temperature (IAT) sensor
- 3 Crankcase pressure sensor
- 4 Nitrogen oxide (NOx) sensors
- 5 Oxygen (O2) sensors
- 6 Manifold absolute pressure (MAP) sensor
- 7 Throttle position sensor (TPS)
- 8 Engine coolant temperature (ECT) sensor
- 9 EGR temperature sensor
- 10 EGR valve position sensor
- 11 Intelligent battery sensor
- 12 DPF Differential pressure sensor
- 13 Crankshaft position sensor
- 14 Camshaft position sensor
- 15 Oil pressure sensor
- 16 Common fuel rail pressure sensor
Mass airflow (MAF) sensor
You can locate the MAF sensor on your Cummins 6.7-liter engine at the air filter box close to the intake manifold.
Its purpose is to measure the airflow entering the engine and send the information to the ECU.
Based on this data, ECU will control the fuel required and engine timing. You will often need to clean it from dirt or oil on its electrodes for accurate performance.
Intake air temperature (IAT) sensor
IAT is a 2-wire sensor to measure the temperature of the air intake. You can find it on the top left side of the intake manifold.
Its probe is inside the second air intake runner, which is the cold air intake side. Therefore, it measures the ambient temperature of the air.
This information is vital for the engine to ensure its correct ignition timing. A faulty IAT can result in increased fuel consumption and symptoms like a hard start or loss of power.
Crankcase pressure sensor
The location of the crankcase pressure sensor is on top of the valve cover, right behind the crankcase vent filter.
It measures the filter’s pressure, and any abnormal pressure value indicates a choked filter.
It also has a role in the regenerative emission process of the engine to measure its pressure and tell ECU to control the regenerative gasses rate into the intake system.
Nitrogen oxide (NOx) sensors
There are 2 NOx sensors on Cummins 6.7-liter engine. The first one is the upstream sensor right after the turbo downpipe.
While the second one is on the tailpipe after the selective catalytic reduction (SCR) system.
They have the purpose of controlling nitrogen oxide emissions to fulfill EPA regulations. However, its failure can result in increased fuel consumption.
Oxygen (O2) sensors
There are also two 6-wire oxygen sensors on the exhaust system of the Cummins 6.7-liter engine. The first one is before, and the second one is after the SCR system.
The upstream part checks the oxygen level in exhaust gasses and sends it to the ECU to optimize the air-to-fuel ratio. The downstream monitors the performance of the SCR to reduce emissions.
Manifold absolute pressure (MAP) sensor
The MAP measures the air pressure changes entering the engine. Its location is on the intake manifold on the driver’s side of the valve cover behind the air horn.
By measuring air pressure, ECU can detect the boost pressure, load on the engine, and increased power demand.
In this way, it can control the correct air-to-fuel ratio for the peak performance of the Cummins 6.7-liter engine.
Throttle position sensor (TPS)
TPS sends the information about the position of the throttle to the ECU. It indicates the demand for fuel by the engine. You can find it directly on the throttle body in earlier models.
However, recent models have electronic sensors located inside the transmission control gearbox.
Engine coolant temperature (ECT) sensor
It senses the engine temperature on a Cummins 6.7 and sends the signal to ECU. It helps regulate the engine temperature as ECU controls the fuel economy and its operation using this information.
You can locate it on the driver’s side of the engine head under the valve cover. Its location can vary according to the model year of the engine.
EGR temperature sensor
The location of the EGR temperature sensor is on the crossover pipe from the EGR cooler to its valve.
It also aims to control the EGR valve based on the temperature of exhaust gasses to ensure engine protection and emissions control. In addition, it requires cleaning before replacement in case of any fault.
EGR valve position sensor
EGR valve position monitors its position on a Cummins 6.7L engine, and ECU controls the valve solenoid accordingly.
It is a part of the EGR valve actuator motor. In addition, 3 hall effect sensors measure the valve position as the motor rotates to change its position according to the ECU signal.
Intelligent battery sensor
You will find it with a negative battery terminal or wire of your vehicle with a Cummins 6.7-liter engine.
Its purpose is to measure the battery’s charge state and the amount of current drawn from it. It also has a thermistor as its part to measure the battery temperature.
It sends the signal to the body control module (BCM) that further communicates with ECU to display the battery status.
DPF Differential pressure sensor
The location of the exhaust gas pressure is right above the exhaust manifold on the left side of the engine.
It is a differential pressure device taking pressure differences on both sides of a diesel particulate filter (DPF).
It measures the exhaust back pressure and sends the data to ECU to start the regeneration process to clean the filter. It can get choked with soot or malfunction due to leaks in its inlet pipes.
Crankshaft position sensor
You can find the crankcase position sensor at the front of the engine on the lower left-hand side of the crank pulley near the harmonic balancer.
The purpose of this part is to determine the firing order of the engine and helps the ECU to ensure the correct ignition sequence, engine RPM, and speed.
Often corrosion or oil contamination of the sensor results in its malfunctioning and requires cleaning or replacement.
Camshaft position sensor
You can find the camshaft position sensor on the Cummins 6.7-liter engine right before the crankshaft position sensor. Both have the same part number and the same specifications.
It has a role in determining the correct injector opening and timing coil to ensure proper firing sequence.
Oil pressure sensor
It can monitor the operation of the oil pump for efficient cooling of the engine and proper lubrication of moving parts.
You can find it behind the oil filter on the back of the engine housing. However, the location is on the other side for earlier models of Cummins 6.7.
Common fuel rail pressure sensor
A fuel rail pressure sensor is present on the end of the common fuel rail of the Cummins 6.7-liter engine.
It measures the amount of fuel in the common rail by measuring its internal pressure with the help of a diaphragm connected to a strain gauge.
In this way, ECU precisely controls the pulse width and duration of the fuel injectors opening and the amount of fuel.