Powertrain, generic · Computer and auxiliary outputs

P0616 Starter Relay A Circuit Low

Check engine lightOn
EmissionsNot relevant
Drive cycleRequired
Limp modeNo

The engine module switches the starter relay coil through its own driver – GM petrol engines with 12 V stop-start use a low-side driver, the Saab 9-4X switches 12 V to the coil. CARB requires output components to be checked for open and short circuits. GM sets the codes after two trips on stop-start engines, while GM diesels (2016) and the Saab 9-4X store them without the check engine light. At Ford an active starter code blocks stop-start. P0616 means the control wire is shorted to ground: GM detects 0.5 Ω or less to ground with the driver off (8 of 10 samples in 2018 and 2025, 40 of 50 in 2019). With a low-side driver the short can energise the relay permanently; with a high-side driver (Saab) the relay no longer pulls in. Saab's check: a test lamp across the coil terminals must flash during cranking.

Likely causes

Control wire chafed through and shorted to ground
Relay coil shorted internally
Moisture or corrosion in the relay or fuse box
Driver in the engine module faulty

Symptoms

  • Engine does not crank
  • Stop-start disabled
  • Possibly blown fuse in the relay circuit
  • Check engine light only with some makers

Repair estimate

DifficultyEasyDIY possible
Parts and labour€15–300
Time0.3–2 h

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

Parts involved

starter relaystarter relay control circuitengine control module

Related codes

P0615P0617P26E5P26F0

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