P2045 OBD-II Trouble Code: Reductant Temperature Sensor Circuit High Input

Our certified mechanics come to you · Get a fair and transparent estimate upfront

Red-stars EXCELLENT RATING ON

Cost of diagnosing the P2045 code

P2045 is a diagnostic trouble code (DTC) for "Reductant Temperature Sensor Circuit High Input". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.

Cars Estimate Credit towards follow-up repair Earliest Availability
Ford$20.00
Toyota$20.00
BMW$20.00
SCHEDULE P2045 DIAGNOSTIC Get a fair and transparent estimate upfront

What the P2045 code means

The P2045 code indicates that your powertrain control module (PCM) has recognized a malfunction in the reductant injector air pressure sensor circuit. The job of the reductant injector is to reduce noxious gases that are expelled through the diesel particulate filter or, more commonly, in your catalytic converter.

What causes the P2045 code?

There may be a number of causes for the P2045 code. You may have broken, loose, burned, or corroded wiring or connectors. This is the most common cause for this code. Some other causes may include a short in your exhaust gas temperature sensor, a faulty sensor, an aftermarket off-road exhaust system that leads to a decrease in back pressure or a severe exhaust leak upstream from your vehicle’s exhaust temperature sensor.

What are the symptoms of the P2045 code?

You will probably notice an excess of black smoke each time you accelerate. However, other than that you will probably not see any other signs that something has malfunctioned.

How does a mechanic diagnose the P2045 code?

You will need several tools, including an OBD-II scanner and a digital volt/ohmmeter, to diagnose this code successfully. Always begin with a careful visual inspection of all wiring and connectors. Replace or repair any damaged, shorted, or corroded wiring and connectors. Next clear the code, start your vehicle and check to see if the code returns. This will tell you whether the malfunction is intermittent.

If the code reappears, continue with a visual inspection of the exhaust gas temperature/pressure sensors and system circuitry. Note carefully where your wires and connectors are located in relation to the hot exhaust components. If all of the exhaust gas temperature/pressure circuitry appears to be working as it should, then proceed with the diagnostic procedure. Using your digital volt/ohmmeter, test the resistance of the exhaust gas temp/pressure sensor. Typical resistance for this sensor should be approximately 150 ohms but make sure to check your manufacturer’s specifications.

Common mistakes when diagnosing the P2045 code

A common mistake is to replace your camshaft, wheel speed sensors, and crankshaft position sensors. Replacing these is not likely to solve the problem. In order to properly diagnose your issue, you will need the proper diagnostic equipment. You can acquire this equipment yourself, or you can take your vehicle to a professional technician who can diagnose the problem for you.

How serious is a P2045

A P2045 is serious and in most cases should be examined by a professional technician. You will also need specialized equipment to diagnose this problem, so unless you have this equipment, you should take your vehicle to a professional technician.

What repairs can fix the P2045 code?

Typically, if there is less than 50 ohms of resistance, you will need to replace the sensor. Observe the resistance level of the sensor as the temperature is elevated to see if it decreases. If the resistance level does not decrease with heat, you know you will need to replace the sensor. However, if everything seems to work so far, turn your vehicle on and check for a voltage and a ground signal at the exhaust gas temperature/pressure sensor electrical connector. If there is no low voltage on the signal wire, you will need to disconnect the PCM connector and do a continuity test on the wire using your digital volt/ohmmeter. If you don’t see any continuity, the PCM may be faulty. But please note that PCM failure is very rare.

Additional comments for consideration regarding the P2045 code

A P2045 can be a complicated issue to solve. It may require that you purchase or rent expensive diagnostic equipment, which still does not guarantee that you will correctly diagnose the problem. It is very important to do the proper amount of research before you attempt any labor on your own.

Need help with a P2045 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online at (https://www.yourmechanic.com) or speak to a service advisor at 1-800-701-6230.

trouble codes
P2045
Check Engine Light

No more waiting rooms! Our mechanics will come to you to diagnose and fix the P2045 code.

SCHEDULE P2045 DIAGNOSTIC
Get a $20 credit for the follow-up repair

Recent Check Engine Light is on Inspection reviews

Excellent Rating


YourMechanic Check Engine Light is on Inspection Service

Average Rating

4.8/5

Number of Reviews

5,395

Rating Summary
4,978
202
50
30
135
4,978
202
50
30
135

Anthony

6 years of experience
18 reviews
Anthony
6 years of experience
Jeep Grand Cherokee - Check Engine Light is on - Carmichael, California
Anthony was great! We are very happy that we chose to go with this company instead of the overpriced and slow service we get from the Jeep dealership. He was on time and did the job just as expected. He identified a couple of other things that need to be done before the problems get worse. We appreciate having a technician give us direct feedback regarding our vehicle, rather than a service advisor (salesperson) that we've had to deal with in the past at the dealership. We'll be booking the addtional services very soon and will definitely request Anthony again now that he is familiar with our vehicle!

Michael

37 years of experience
113 reviews
Michael
37 years of experience
Subaru Forester - Check Engine Light is on - Santa Fe Springs, California
Michael was punctual and courteous. He knows what he’s doing and I would absolutely recommend him to anyone.

Anthony

6 years of experience
18 reviews
Anthony
6 years of experience
BMW 740Li - Check Engine Light is on - Roseville, California
Very helpful in finding out the fault codes in my bmw 740 li. It was simple fix and that the two tube hose just had to be connected and my drive train malfunction went away. This saved me from having to go the an expensive dealership. Anthony has a good attitude about his work.

Breck

19 years of experience
613 reviews
Breck
19 years of experience
Ram 1500 - Check Engine Light is on - Houston, Texas
Breck did a great job working on my truck. Showed up on time, found any issues I had on my truck and explained everything to me so that I understood what was going on. Went above and beyond, definitely will book him for future appointments.


More related articles

P2161 OBD-II Trouble Code: Vehicle Speed Sensor B Intermittent/Erratic
P2161 P2161 trouble code definition Vehicle Speed Sensor B Intermittent/Erratic What the P2161 code means P2161 is an OBD-II generic code for the engine control module (ECM) detecting the vehicle speed sensor 2 or B giving an intermittent or erratic...
P3484 OBD-II Trouble Code: Cylinder 11 Deactivation/Intake Valve Control Circuit High
P3484 code means cylinder 11 was deactivated during certain driving conditions due to low oil pressure, engine condition, or electrical components.
P0902 OBD-II Trouble Code: Clutch Actuator Circuit Low
What What the P0902 code means The P0902 is a generic OBD-II powertrain code, which means it applies to all makes and models of vehicles from 1996 to the present. What causes the P0902 code? There may be one...

Related questions

Replaced the transmission and now car won't start

I highly doubt the powertrain control module (PCM) (also known as the ECU) is bad. Code P025A indicates a problem with a faulty fuel pump or its circuit, which could definitely be causing the problems you are having. A...

Codes P2106 and P0720

Hi. The codes you have deal with the electronic throttle body having problem with the throttle control actuator and the output speed sensor. Both of these codes will cause the idle to be abnormal and cause the vehicle to shift...

Check engine light with a code about insufficient temperature P0126 to the engine.

Hi there. The coolant temperature sensor (CTS) is not working correctly. The sensor is sending a signal that the engine is already warm and when the engine first starts up, it needs more fuel a rich mixture to produce more...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com