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 for $70.00. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $30.00 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$70.00$30.00
Toyota$70.00$30.00
BMW$70.00$30.00
SCHEDULE P2045 DIAGNOSTIC Get a fair and transparent estimate upfront

check engine light

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

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

4.5/5

Number of Reviews

4,004

Rating Summary
3,661
169
45
25
104
3,661
169
45
25
104
Richard

Richard

10 years of experience
441 reviews
Richard
10 years of experience
Very professional and gave helpful information.
2003 HYUNDAI SONATA - CHECK ENGINE LIGHT IS ON - LAS VEGAS, NEVADA
Michael

Michael

20 years of experience
5 reviews
Michael
20 years of experience
Michael was sent out on a SUnday 01/27/2019 to find out why, after the car was serviced for the check engine light, the check engine light was on again and the car was running rough as compared to before the service. He found the main problem almost immediately and explained what was happening and the likely reason it was happening. He also road tested the acr and revealed that there were other issues of which I should have been made aware and was not when the mechanic was out the day before, 01/26/2019. He was excellent at describing the problem, why it happened and what had to be done. I would reccomend him any time!!!!!!!!!!
2001 MERCURY GRAND MARQUIS - CHECK ENGINE LIGHT IS ON - LAS VEGAS, NEVADA
Honorio

Honorio

16 years of experience
658 reviews
Honorio
16 years of experience
Honorio was very professional and knowledgeable.
1993 TOYOTA PICKUP - CHECK ENGINE LIGHT IS ON - SANTA CLARA, CALIFORNIA
Chris

Chris

19 years of experience
1240 reviews
Chris
19 years of experience
great !
1996 ISUZU RODEO - CHECK ENGINE LIGHT IS ON - HUNTINGTON BEACH, CALIFORNIA

More related articles

How to Get a Louisiana Driver's Permit
s licensing program. The first step in this program is to obtain...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
Auto Safety Tips
Driving is more than a way to get from point A to point B. Owning and driving a car can also be a highly enjoyable experience. Whether a person is driving...

Related questions

Q: How long and what is the process to replace a fuel pressure sensor?

A professional mechanic would require roughly 5 hours. (If just the regulator is replaced that takes about 1 hour). Some parts, as noted below, cannot be re-used, you need a precision inch pound torque wrench, FSM instructions (and TSB updates...

Q: There is a misfire on cylinder 2. I changed the cylinder and spark plug but am still having the misfire.

Hello. If you switched the spark plugs relating to two different cylinders and the same cylinder exhibited the same signs, then the issue is related to the other components on that cylinder. The test you performed was a great one....

Q: Q: Check engine light on

There area number of things that can cause a misfire such as low fuel pressure, vacuum leaks, faulty spark plugs or wires, a bad crankshaft position sensor, bad camshaft position sensor, faulty fuel injectors and many others. The most efficient...

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