The OBD2 code P2033, related to “Exhaust Gas Temperature (EGT) Bank 1 Sensor 2 Circuit High Voltage,” indicates an issue with the second exhaust gas temperature sensor’s electrical circuit, signaling higher than expected voltage readings.
This code is particularly relevant in diesel vehicles, where monitoring exhaust gas temperature is crucial for the proper operation of systems like the Diesel Particulate Filter (DPF) and exhaust after-treatment. Let’s delve into the specifics based on the provided service cases from GMC, Chevrolet, and Ford trucks.
P2033 quick overview
| Meaning | P2033: Exhaust Gas Temperature Sensor 2 Circuit High Voltage (Bank 1) |
| Is it serious? | Yes, this code could indicate a malfunction that affects the vehicle’s exhaust after-treatment system, potentially leading to reduced efficiency or damage to the DPF. |
| Possible causes | – Faulty EGT sensor – Wiring issues (shorts, damage, or disconnections) – Problems with the Diesel Exhaust Fluid (DEF) system components – ECM (Engine Control Module) calibration or failure |
| How to diagnose? | Inspect the EGT sensor and its wiring for damage or corrosion. Perform a resistance check on the sensor to assess its functionality. Check the DEF system and related installations for issues that might affect sensor readings. Update the ECM with the latest software calibrations if applicable. Conduct a service regeneration of the DPF if codes related to the DPF are present. |
P2033 Meaning
Imagine your vehicle’s exhaust system as a complex network that cleans up the exhaust gases before they exit the tailpipe. The EGT sensor plays a critical role in this network by measuring the temperature of these gases, ensuring that the cleaning process, such as burning off soot in the DPF, happens efficiently.
When the P2033 code pops up, it means there’s a hiccup in this process. The sensor might be sending incorrect signals due to being faulty, or there could be wiring issues. It’s like having a faulty thermometer that reads too high temperatures; it can cause the system to react incorrectly, potentially harming the vehicle’s performance and the environment.
Car Diagnostics Training
- Car Electrical basics
- OBD-II scanner basics
- How to use an OBD reader
- Introduction to a Bi-directional Scan tool
- OBD scanner buyer’s guide + discounts
How to fix P2033 – learn from mechanics
I looked into P2033 service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.
Case #1: GMC
Vehicle Information 2013 GMC Sierra 3500 HD SLT 6.6L
Issue + Repair History
- Truck recently had a DEF tank heater installed at another shop.
- MIL lamp on with code P2033 00 for exhaust gas temp sensor 2 high voltage.
- Technician pulled down the DEF tank to inspect wiring but found nothing pinched.
Other OBD2 Codes + Test Results
- P2033 00 – Exhaust gas temp sensor 2 high voltage
- Sensor is receiving 5V feed.
Mechanic Suggestions
- Short the body side harness and monitor scan tool reading to verify wiring integrity.
- Perform a resistance check on the sensor itself.
Final Fix Replaced the exhaust gas temperature sensor 2 as it was found to be open, resolving the issue.
Case #2: Chevrolet
Vehicle Information 2007 Chevrolet C4500 Kodiak C4C042 6.6L
Issue + Repair History
- Truck had spacers installed between the catalytic converter and front exhaust pipe by telecommunication service personnel.
- MIL lamp on with codes P2463, P244B, P2033, and P0546.
- Technician suspects a clogged Diesel Particulate Filter (DPF) due to temperature sensor codes inhibiting regeneration.
Other OBD2 Codes + Test Results
- P2463 – Undocumented
- P244B – Undocumented
- P2033 – Diesel Particulate Filter (DPF) temperature sensor 2 circuit problem
- P0546 – Diesel Particulate Filter (DPF) temperature sensor circuit problem
Mechanic Suggestions
- Fix the DPF temperature codes by checking for broken wires, bad sensors, or a possibly faulty ECM.
- Remove the spacers installed between the catalytic converter and front exhaust pipe.
- Update the ECM with the latest calibrations to enable a service regeneration with code P244B set.
- Perform a service regeneration with a Tech2 scanner to clean the DPF. Ensure the truck is parked outside and away from other vehicles during this process.
Final Fix Updated the ECM with the latest calibrations and performed a service regeneration with a Tech2 scanner, cleaning the DPF and resolving the issue.
Case #3: Ford
Vehicle Information 2008 Ford F-350 Super Duty Lariat 6.4L
Issue + Repair History
- Truck came in for head gasket/egr cooler failure, cab-off head repair performed.
- After bleeding fuel system, truck starts fine but MIL comes on with a loppy idle.
- Codes P242D, P0546, P2033, and P2455 repeatedly return.
- All grounds and connectors undone for the job have been checked and rechecked.
Other OBD2 Codes + Test Results
- P242D – EGT sensor circuit high B1 S3
- P0546 – EGT sensor circuit high B1 S1
- P2033 – EGT sensor circuit high B1 S2
- P2455 – DPF pressure sensor high
Mechanic Suggestions
- Check for antifreeze, oil, or other contaminants that may have spilled into connectors during head repair causing voltage bleed over.
- Back probe connectors and check for ground. If no ground, jump wire to ground to check if PID values change, indicating a lost ground. Check for damage on connector C110 pin 24.
- Drop down pipe from the turbo to see if the truck runs better, indicating a possible plugged DPF from EGR failure. Clean DPF and DOC if necessary.
- Perform a vacuum test on the EGR and test the EGR DPFE and solenoid pressure sensor using a multimeter.
Final Fix Found fuel had bled into one of the harness connectors. Cleaned, dried, and reconnected the harness, resolving the issue.
How to diagnose P2033
I made you an overview of solving this DTC, based on all the advice that was suggested by certified mechanics to address this issue in previously mentioned service cases.
| Diagnostic Step | Brief Explanation |
|---|---|
| Inspect EGT sensor and wiring | Look for physical damage or contamination that could impair signal transmission. |
| Perform resistance check on the sensor | A quick test to verify if the sensor is functioning within its intended parameters. |
| Update ECM software | Ensures the vehicle’s computer is operating with the latest instructions for managing exhaust gases. |
| Service regeneration of the DPF | Clears the DPF of accumulated particulate matter, which can influence EGT readings. |
| Check DEF system installations | Recent modifications can affect exhaust system performance, including EGT sensor readings. |
Addressing a P2033 code involves careful inspection of the sensor, wiring, and related systems to ensure accurate diagnosis and repair. Given the potential complexity and the need for specialized equipment (like a Tech2 scanner for service regeneration), it’s often best for vehicle owners to seek professional assistance when dealing with exhaust-related codes. Properly resolving issues indicated by P2033 not only prevents further damage to the exhaust system but also ensures the vehicle operates efficiently and within emission standards.
Car Diagnostics Training
- Car Electrical basics
- OBD-II scanner basics
- How to use an OBD reader
- Introduction to a Bi-directional Scan tool
- OBD scanner buyer’s guide + discounts
I test OBD-II scanners and make DIY Engine diagnostics guides to help you solve your car problems without having to depend on the mechanic. A lot of them will try to scam you or are just no help at all. About Juraj Lukacko