Ram Cummins P2033: Exhaust Gas Temperature Sensor Circuit High
P-Code P2033 (FMI N/A) — Exhaust Gas Temperature Sensor Circuit High Bank 1 Sensor 2
Quick Answer
P2033 means an exhaust gas temperature sensor circuit on the Ram 6.7L Cummins is reading voltage pegged high, typically an open circuit from heat-damaged wiring. It's Medium severity and can affect DPF regeneration timing, though the engine keeps running.
Overview: Ram Cummins P-Code P2033
Exhaust gas temperature sensors are placed at multiple points along the aftertreatment system on the 6.7L Cummins to give the PCM real-time visibility into exhaust heat as it moves through the DPF and SCR components. ProfessionalDieselRepair.com sees P2033 most commonly caused by heat-damaged wiring given the sensor's proximity to the hottest sections of the exhaust, and while there's no immediate drivability symptom, addressing it promptly helps keep regeneration timing accurate.
Repair Snapshot
Time
1 - 2 Hours
Difficulty
Intermediate
Parts Cost
$70 - $230
Dealer Labor
$380+
Tools Required
- Cummins INSITE
- Multimeter
- Diesel Laptops Diagnostic Software
- Heat-Resistant Gloves
What P-Code P2033 Means
P2033 means the second exhaust gas temperature sensor in the exhaust stream is reading voltage pegged high, which on most systems indicates an open circuit rather than a genuinely high temperature. This sensor helps the PCM monitor aftertreatment component temperatures and manage DPF regeneration, so the fault can interfere with regen timing and accuracy. The MIL illuminates but the engine keeps running normally.
Symptoms Drivers Notice
- MIL illuminated
- Possible DPF regeneration timing changes or hesitancy to initiate regen
- No immediate drivability change in most cases
- Potential inaccurate exhaust temperature readings on diagnostic scans
Most Likely Root Causes
Heat-damaged sensor wiring near the exhaust system
CommonSustained high exhaust temperatures gradually crack wire insulation, eventually breaking the conductor and opening the circuit.
Corroded or loose sensor connector
CommonHeat cycling and road grime degrade connector seals over time, corroding pin contacts and creating an intermittent or open connection.
Failed sensor element
OccasionalThe thermocouple or thermistor element inside the sensor can fail from repeated extreme heat cycling.
Physical damage from a recent exhaust or DPF repair
RareSensor wiring or connectors can be accidentally damaged during nearby component service if care isn't taken during reassembly.
Common Misdiagnoses (Don't Waste Parts)
Replacing the DPF due to perceived regeneration problems
Why it happens: A parts-cannon mindset assumes any exhaust temperature fault relates to a failing DPF rather than a sensor issue upstream.
Do this instead: Verify the sensor circuit is actually open before assuming any real DPF or regeneration performance problem exists.
Skipping the wiring check because the sensor tests fine off the truck
Why it happens: Techs assume the sensor must be bad once removed without checking harness continuity separately.
Do this instead: Test reference voltage and ground at the harness connector independently of the sensor before concluding the sensor is at fault.
Ignoring the fault since there's no obvious drivability change
Why it happens: Without a noticeable symptom, this code often gets deprioritized.
Do this instead: Address it promptly since prolonged operation without accurate EGT data can affect regeneration reliability and long-term aftertreatment health.
Master Tech Commentary
Mechanic's Notes
Shop tip from ProfessionalDieselRepair.com: EGT sensor wiring on the 6.7L Cummins lives right next to the DPF canister, one of the hottest spots on the truck, so cracked insulation right at the heat shield boundary is far more common than an actual failed sensor element. Inspect the last several inches of harness before ordering a new sensor.
Step-by-Step Diagnostic Procedure
- Step 1: Scan for codes with Cummins INSITE or a comparable tool and confirm P2033, noting the specific sensor location (typically before or at the DPF).
- Step 2: Inspect the sensor connector for corrosion, and check the wiring for heat damage near the exhaust piping.
- Step 3: Unplug the sensor and verify the expected reference voltage and ground are present at the harness side.
- Step 4: Check sensor resistance with a multimeter against spec, since an open EGT sensor will read infinite resistance (OL), consistent with a voltage-high fault.
- Step 5: Replace the sensor or repair the harness as needed, clear the code, and monitor regeneration behavior on the next drive cycle.
Live Data & Freeze-Frame Tips
Compare the affected EGT sensor reading against adjacent temperature sensors in the exhaust path using your diagnostic tool - a stuck-high or unrealistic flat value confirms an open circuit rather than an actual temperature anomaly.
Safety Warnings
- Allow the exhaust system to cool completely before working near EGT sensors - temperatures can remain dangerously hot well after shutdown.
- Wear heat-resistant gloves when handling sensors and connectors near the exhaust piping.
- Support the vehicle properly on a lift or jack stands when accessing components underneath.
- Avoid sensor service immediately after a regeneration event due to extreme residual heat.
When to Limp In vs Tow
Towing is not necessary for this code. Address it promptly to maintain reliable regeneration timing and avoid any secondary aftertreatment complications down the road.
Prevention Tips for Fleets & Owner-Operators
- Inspect EGT sensor wiring for heat damage during routine PM inspections.
- Ensure heat shields are properly reinstalled after any exhaust or DPF service.
- Address minor sensor codes early before a chafe or crack point worsens into a full open circuit.
- Keep a record of which EGT sensor locations have needed replacement to spot recurring heat-damage patterns.
Related Fault Codes
P2032
Exhaust gas temperature sensor circuit low, the opposite electrical fault on the same sensor circuit.
P2459
DPF regeneration frequency fault, worth checking since inaccurate EGT data can affect regen timing decisions.
P203B
Reductant injector performance fault, another aftertreatment sensor-related code worth cross-checking on the same exhaust system.
Frequently Asked Questions
Can I drive with P2033 active?
Yes, the engine runs normally with this code, though regeneration timing decisions may be affected since the PCM is missing accurate data from this temperature sensor.
How do I reset this code without a scanner?
You need a scan tool to properly diagnose and confirm the repair, since simply clearing the code without fixing the open circuit will result in the fault returning.
Does this code affect fuel economy?
Some PCM calibrations run more conservative default strategies when a temperature sensor is unavailable, which can slightly affect fuel economy until the sensor is repaired.
Where is this specific sensor located?
Bank 1 Sensor 2 typically refers to the second EGT sensor in the exhaust path, often located at or near the DPF inlet, though exact placement can vary by model year - check your specific wiring diagram to confirm.
How expensive is this sensor to replace?
EGT sensors are generally inexpensive, typically well under $200 including labor, making this one of the more affordable aftertreatment-related repairs.
Can heat exposure alone cause this fault without any accident or damage?
Yes, normal long-term exposure to high exhaust temperatures is enough to eventually crack wire insulation and cause an open circuit, even without any collision or impact damage.