Powertrain, generic (extended)

P23ED Camshaft B Position Signal Output Circuit Low (Bank 1)

Check engine lightUsually off

EmissionsNot relevant

Drive cycleNot required

Limp modePossible

With P23ED the ECM detects that its camshaft B output for bank 1 reads low although it has released the line to go high. Most often a harness section rubbing through to the engine block, a crushed connector pin or a shorted input in the receiving module is to blame. Measured analogies come from GM: the bank 1 camshaft A output code P2615 uses a ground resistance of at most 0.5 ohm, requires the engine to be out of crank and is rated Type C, so no warning lamp. Whether makers who use P23ED light the MIL is not published. Because the sensor feeding the ECM is not involved, replacing the camshaft sensor will not clear the code; a voltage-drop test of the output line between both modules is the sensible first step.

Likely causes

Harness rubbed through against the engine block

Crushed or bent connector pin touching ground

Shorted input in the receiving module

ECM output stage damaged

Symptoms

Code stored, engine performance unaffected
Downstream module reports missing camshaft signal
Possible fallback behaviour in transmission or hybrid functions

Repair estimate

DifficultyMediumWorkshop job

Parts and labour€50–900

Time0.5–3 h

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

Parts involved

engine control modulecam position signal b b1 outputwiring harness

Related codes

P23EC P23EE P23EA P23F0 P2615

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