OBD-II trouble code
P2035: Exhaust Gas Temperature Sensor Circuit Low Bank 2 Sensor 2
A short to ground needs somewhere to touch, and this is the longest, most-routed, most-clipped exhaust temperature circuit on the vehicle. The wiring deserves suspicion here in a way it does not on shorter runs.
Quick facts
- System
- Powertrain
- Category
- Exhaust / Aftertreatment
- Severity
- Medium severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $160 – $900
- DIY difficulty
- Advanced DIY
Browse every code in P2000–P20E8, or start from the full code library.
What does P2035 mean?
Two facts about this particular circuit shape the whole diagnosis, and neither is about the sensor.
The first is geometry. Bank 2 is the side of the engine that does not contain cylinder one, and on the overwhelming majority of installations its exhaust has further to travel. On a transverse V6 the rear bank's downpipe has to come round or under the engine. On a longitudinal V8 the passenger-side pipe crosses beneath the transmission tunnel. Either way, the harness branch feeding this sensor is longer than its bank 1 equivalent, follows more bends, passes more brackets, and is secured by more clips — and it runs alongside things that are hot, things that vibrate on their own mounts, and things that move relative to the body.
That matters because of the second fact: this is a low-side code, and low means the signal is being pulled toward ground. Something is providing an unintended conductive path. Broken conductors do not do that; contact does. So the physical question is not whether a wire has failed but where it has found something to touch — and the circuit with the most opportunities to touch something is the one most likely to have done it. Every lost clip is a length of unsupported lead resting on a pipe. Every bracket edge is an abrasion point. Every place the harness crosses between engine-mounted and body-mounted structures is somewhere that flexes a few millimetres on every gear change for the life of the vehicle.
The practical outcome is a strong prior. On a bank 2 low-side fault, the wiring is the likelier cause and the sensor is the likelier casualty of a misdiagnosis. That prior is worth holding onto because of the third thing about this position: cost asymmetry. The part is identical to bank 1's and costs the same. The labour is not — the sensor typically sits in the most awkward corner of the engine bay or against the bulkhead, and getting to it can take several times as long. Replacing it on suspicion, then discovering the short is in a chafed section eighteen inches upstream, means paying for that access twice.
There is a two-minute test that resolves it before anything is dismantled. Unplug the sensor at its connector and watch the live reading. With nothing connected the circuit is open, so the value should shoot to the opposite extreme. If it does, the harness between the connector and the module is clean and the fault is in the sensor or its own short pigtail. If the reading stays pinned low with the sensor out of circuit, the short is in the harness and a new sensor cannot possibly fix it. Doing that test first is the single highest-value decision on this code.
Beyond the electrics, the consequence is the same as any missing filter-inlet feedback: regenerations stop working properly on that side, soot accumulates, and what starts as a wiring fault turns into a filter problem if it is left long enough. The vehicle will not warn you dramatically. It will simply drive normally while one filter fills up.
Common causes
- Signal conductor grounded against the bank 2 downpipe where a retaining clip has been lost
- Insulation abraded at a bracket or heat shield edge along the long bank 2 harness run
- Chafe at a point where the harness crosses between engine-mounted and body-mounted structure
- Water and salt bridging the connector terminals in an exposed underfloor location
- Sensing element internally short-circuited after long high-temperature service
- Lead pinched or crushed during transmission, subframe or starter work on the same side
- Perished connector seal letting moisture reach the contacts
- Corroded terminals creating a low-resistance leak path rather than a hard short
- Damage from a heat shield that has come adrift and is resting against the harness
- Incorrect replacement sensor reading low across its whole range
Symptoms
- Check engine light with the vehicle otherwise driving normally
- Live data showing bank 2's filter inlet temperature pinned low while bank 1 reads sensibly
- Regenerations stopping, or completing only on the opposite bank
- Soot load on the bank 2 filter climbing steadily relative to bank 1
- Fault that appears over bumps, on rough surfaces or under hard acceleration
- Intermittent behaviour that follows wet or salted road conditions
- Restriction or backpressure codes emerging on the affected bank weeks later
- Visible chafe marks, missing clips or a lead resting against the pipe on inspection
- Fault first noticed shortly after driveline or exhaust work on that side of the vehicle
Diagnostic steps
- 1.Unplug the sensor and watch the live reading before doing anything else. If it swings to the hot extreme the harness is sound and the fault is the sensor; if it stays pinned low the short is in the wiring and a new sensor will not help.
- 2.Compare both banks' filter inlet readings on a cold vehicle. Both should sit near ambient, and the disagreement identifies the faulty circuit without needing a specification.
- 3.Trace the full bank 2 harness run visually, since it is longer and more exposed than bank 1's. Look for missing clips, unsupported lengths resting on the pipe, and abrasion where the loom crosses brackets.
- 4.Pay particular attention to any point where the harness passes between engine-mounted and body-mounted structure. That joint flexes for the life of the vehicle and is a repeat offender for chafe.
- 5.Measure insulation resistance from the signal conductor to ground with the sensor disconnected. A hard short reads near zero; corrosion or a damp connector reads low but finite.
- 6.Inspect the connector for water, salt residue, green corrosion and perished seals, and test it wetted if the fault has followed the weather.
- 7.Flex and pull the harness section by section while watching live data. A chafe that only makes contact under vibration will pass a static insulation test.
- 8.Check the sensor's own resistance against specification and confirm it changes smoothly as the tip is warmed.
- 9.Confirm the sensor is tight in its boss with no leak at the joint, since diluted gas produces a low reading with no electrical fault present.
- 10.Repair and properly re-clip the harness rather than only replacing parts, then command a regeneration and confirm both banks complete.
Repair cost
$160 – $900
Diagnosis is $110 to $220. The disconnect test that separates harness from sensor costs nothing and should always come first here, because labour is the variable that matters: the sensor is $60 to $260 but access on bank 2 commonly runs 1 to 3 hours. Harness repair — new section, connector body, seals and clips — is $120 to $400 and is the correct fix in a large share of low-side faults on this run. If the bank 2 filter has been loading unnoticed, add a forced regeneration at $150 to $400, or cleaning from $900 in a neglected case.
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DIY vs shop
This is an advanced DIY job. It typically requires specialty tools, scan-tool access, lifting equipment, or careful sequencing to avoid causing new failures. Plan for extended downtime and have a backup vehicle. Most owners are better served by a shop that has done this repair before.