Powertrain, generic · Computer and auxiliary outputs

P06FF Economy Mode Lamp Control Circuit

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

When the engine module switches a lamp through its own wire, it checks the output driver electrically like other lamp outputs: with the lamp off the line must carry supply voltage, with it on nearly 0 V – GM's MIL driver, for example, flags an open circuit at 200 kΩ or more. It cannot see whether the bulb lights, and on cars that send the lamp command over CAN such faults appear as U codes. P06FF concerns an economy indicator such as an ECO lamp that the engine module switches directly; the code reports a fault in its control circuit. It should not be confused with a body electrics 'economy mode' that saves battery energy. No manufacturer document available to us uses this code; the description follows CARB's output check and other lamp circuits. Driving is not affected.

Likely causes

Wire or connector to the lamp open or shorted
Lamp or instrument cluster faulty
Engine module

Symptoms

  • ECO indicator not working or permanently lit
  • No effect on driving

Repair estimate

DifficultyEasyDIY possible
Parts and labour€30–250
Time0.3–1.5 h

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

Parts involved

indicator lamp circuitinstrument clusterengine control module

Related codes

P06F4P0650P0654

References: law.cornell.edu, gsi.ext.gm.com.