Powertrain, generic (extended)

P2559 Engine Coolant Level Sensor/Switch Circuit High

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P2559 is the high-voltage fault in the circuit of the coolant level sensor or switch. In the Deutz EMR L1 code list it appears as P2559-12 under SPN 111 meaning the line is shorted to battery plus; Deutz keeps open circuits under P2558 on that input, so a high reading there really points to contact with a positive feed. On other designs, especially simple float switches with a pull-up resistor, a broken wire could also produce a high level, so the maker's circuit logic decides what to measure. Wiring near the expansion tank often runs close to battery or fan feeds, which makes chafing a likely cause. P2558 covers the low side, P2557 an implausible but in-range value, P2556 the general circuit fault and P2560 a genuinely low coolant level. Until fixed, the low coolant warning may stay silent.

Likely causes

Signal line chafed against a positive feed
Open circuit on pull-up type switch designs
Level sensor internally faulty

Symptoms

  • Low coolant warning does not work
  • Warning lamp or message for the level sensor

Repair estimate

DifficultyEasyDIY possible
Parts and labour€20–250
Time0.3–1.5 h

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

Parts involved

coolant level sensorsensor wiring

Related codes

P2556P2557P2558P2560

References: serdia.deutz.com, static.nhtsa.gov.