Powertrain, generic (extended)

P2043 Reductant Temperature Sensor A Circuit Range/Performance

Check engine lightOn

EmissionsRelevant

Drive cycleRequired

Limp modeNo

P2043 flags a temperature reading from reductant sensor A that is electrically valid but does not fit the other temperatures the system knows. Deutz stores it as P2043-64, a plausibility error of the DEF temperature sensor in the SCR system (SPN 4337), separate from the tank sensor check P205B-64. Ford uses the code on 2011–2012 F-250/F-350 and 2011–2015 F-450/F-550 with the 6.7L diesel built up to 9 Dec 2014: per bulletin 18-2190, P2043 on its own only needs a PCM reprogram, while P2043 together with P205C or P205D calls for a new reductant heater and sender assembly as well. A plausibility code alone therefore often points to software or a cold soak case rather than to a broken part. Open and shorted circuits are P2042, P2044 and P2045.

Likely causes

Engine control software, fixed by reprogramming (Ford 6.7L)

Temperature sensor drifting or slow to respond

Frozen or partly thawed DEF around the sensor

Contact resistance in the connector shifting the reading

Symptoms

MIL, often without noticeable driving change
DEF heater may run at the wrong time

Repair estimate

DifficultyMediumWorkshop job

Parts and labour€0–900

Time0.4–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

reductant temperature sensor

References: serdia.deutz.com, static.nhtsa.gov, law.cornell.edu.