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

Our certified mechanics come to you · 12-month, 12,000-mile warranty

SCHEDULE P2045 DIAGNOSTIC 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 1-800-701-6220.

trouble codes
P2045
Check Engine Light

Fast and easy Check Engine Light is on Inspection service at your home or office.

SCHEDULE P2045 DIAGNOSTIC
Get a fair and transparent estimate upfront

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

4,810

Rating Summary
4,424
187
47
28
124
4,424
187
47
28
124

Joel

19 years of experience
741 reviews
Joel
19 years of experience
Acura RL - Check Engine Light is on - Jacksonville, Florida
very knowledgeable and precise. able to fix electrical issues in my car. Right on time for the appointment.

Christopher

15 years of experience
41 reviews
Christopher
15 years of experience
Honda Accord - Check Engine Light is on - Fairburn, Georgia
Christopher was excellent! He explained everything in detail to make sure I understood. He was professional and provided me with the next course of actions to resolve my care issues. I'm glad he was sent to service my car.

Alexander

18 years of experience
58 reviews
Alexander
18 years of experience
Saab 9-7x - Check Engine Light is on - Kissimmee, Florida
He was very friendly and very helpful . I felt like it was being around a close friend , also gave me so very good advice on my car & future advice about it . Highly recommend mechanic, would use his services again .

Matthew

31 years of experience
639 reviews
Matthew
31 years of experience
Jeep Patriot - Check Engine Light is on - Norfolk, Virginia
Matthew was on time which was a relief, he is very knowledgeable and was easy to understand what was wrong and what was being done. I am recommending to friends and family due to the great experience Matthew gave me. Extremely professional 10/10

More related articles

P0481 OBD-II Trouble Code: Cooling Fan 2 Control Circuit Malfunction
P0481 means a problem with the control circuit for cooling fan 2. Some causes are faulty cooling fan or damage to the wire connecting the cooling fan.
P0677 OBD-II Trouble Code: Cylinder 7 Glow Plug Circuit
P0677 means that there is an issue with the glow plug circuit due to faulty relays, timer, module, or electrical components.
P0452 OBD-II Trouble Code: Evaporative Emission Control System Pressure Sensor Low Input
P0452 means there is a issue with the fuel tank pressure sensor or the evaporative pressure sensor. Some causes are a loose fuel gap or a vacuum leak.

Related questions

Do I need a new alternator?

I would recommend having your alternator tested for proper function with a digital multimeter by a qualified technician. This test will determine if the alternator is charging the battery at the proper levels. If the alternator is not charging the...

service engine soon

There is a TECHNICAL SERVICE BULLETIN for the problem and need to reprogram the PCM to a new level. The code is for a cam sensor signal being misread by computer and this TSB needs to be done before replacing...

Check Engine Light

If your vehicle's check engine light illuminates, there is a malfunction that should be diagnosed and repaired. If the check engine light is flashing, that means there is a serious fault, such as cylinder misfiring, that requires immediate repair. Misfiring,...

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.

1-800-701-6230 · hi@yourmechanic.com