Code
B1717
HUMMER
B — Body
Mirror Power Fold Control Switch Shorted Low
AI status
Completed
Completed
100%
Causes
- Damaged or shorted mirror fold switch
- Damaged wiring harness (chafing, pinched, broken insulation) causing short to ground
- Corroded/seized connector or water intrusion at mirror or door harness
- Faulty Body Control Module / Mirror Control Module (less common)
- Aftermarket accessory or recent door service/repair that disturbed wiring
Symptoms
- Fold/unfold mirror does not operate or operates intermittently
- DTC B1717 present in scan tool and may reappear after clearing
- Mirror may be stuck in folded or unfolded position
- Other mirror-related functions (heating, indicators) may be affected if sharing circuits
- Possible blown fuse if short is heavy-duty
What to check
- Retrieve freeze frame and accompanying DTCs with a scan tool; note conditions (ignition state, door position)
- Visually inspect mirror housing, door harness (bend area), and connectors for damage, corrosion or water
- Check relevant fuse(s) for the mirror system
- Attempt to operate mirror fold while monitoring DTC and observing any changes
- Disconnect mirror switch/assembly and see if code clears or changes
Signal parameters
- With ignition ON, reference power present at switch connector (approx. battery voltage ~12V) when circuit is commanded high
- A healthy fold-switch signal should toggle between near 0 V (low) and near battery voltage (high) when the switch is operated
- Short-to-ground condition: signal remains near 0 V regardless of switch position
- Short-to-battery/pulled-high condition: signal remains near battery voltage regardless of switch position
- When disconnected, expected open-circuit/high resistance on the switch signal line unless the switch is actuated
Diagnostic algorithm
- Safety first: ensure vehicle is in Park, key off when disconnecting connectors and follow manufacturer safety procedures.
- Connect scan tool, read DTCs and freeze frame, record data and clear codes to confirm recurrence.
- Visually inspect mirror assembly, switch and door harness at hinge area for damage, corrosion, or water entry.
- Check fuses related to mirror power/folding—replace if blown and inspect cause before driving.
- With ignition ON, backprobe the switch signal connector and observe voltage while operating the fold switch: verify signal changes between near 0 V and battery voltage. If signal is constant low (near 0 V), suspect a short to ground.
- If shorted low is present, disconnect the mirror assembly/switch and re-test the circuit at the harness connector. If voltage returns to normal when mirror is disconnected, the mirror/switch assembly is likely faulty—replace or repair.
- If the fault remains with the mirror disconnected, perform continuity checks from the harness pin back to the BCM/mirror control module to locate a short to ground. Use a wiring diagram to identify pin locations.
- Wiggle test the door harness through the full travel of the door while monitoring the signal and watch for intermittent changes; inspect for chafed wires at the door hinge.
- Repair identified wiring damage (repair splice, replace harness) or replace faulty switch/mirror assembly as required.
- After repairs, clear codes and verify operation of fold function and absence of B1717. Re-scan after road test and multiple fold cycles.
Likely causes
- Faulty mirror power fold switch (internal short to ground)
- Harness pin or wire shorted to door ground (chafed insulation at hinge/door jamb)
- Connector terminal pushed out/corroded allowing grounding
- Water intrusion into mirror housing causing a low-resistance path to ground
Fault status
Status
Circuit indicates a low voltage (short to ground) on the mirror power fold control switch input. The control module has detected the signal below its threshold and logged B1717.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
Similar codes
Repair manuals
Manual library for HUMMER
138
Browse 138 HUMMER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.
HUMMER
-
HUMMER: 2009
-
HUMMER: 2008
-
HUMMER: 2007
-
HUMMER: 2005
-
HUMMER: 2004
-
HUMMER: 2000
-
HUMMER: 1999
-
HUMMER: 1994
-
HUMMER: 1993
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email