Powertrain, generic · Computer and auxiliary outputs

P06ED Engine RPM Output Circuit Low

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

The engine module turns the crankshaft signal into a cleaned-up square wave for the tachometer, transmission or body-builder modules – Saab's 1999 9-3, for example, sends two pulses per revolution, about 30 Hz at idle. P06ED means this output is too low, typically shorted to ground, so it can no longer switch high. It is the counterpart of P0654 (open circuit) and P06EE (high). CARB requires output circuits to be checked; the signal is emission-relevant only if a receiving module uses it for emission functions. No manufacturer document available to us uses this code; the description follows CARB, the component and P0654. The tachometer then reads zero or jumps, and modules using the signal lose it, while the engine runs normally.

Likely causes

Speed output wire chafing against ground
Receiver (instrument, add-on device) shorted internally
Aftermarket tachometer or accessory wired wrongly
Engine module driver stage

Symptoms

  • Tachometer at zero or jumping
  • Other modules without speed signal
  • Engine runs normally

Repair estimate

DifficultyMediumDIY possible
Parts and labour€40–300
Time0.5–2 h

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

Parts involved

engine speed output circuittachometerengine control module

Related codes

P0654P06EEP0650

References: law.cornell.edu, saabwisonline.com.