OBD-II code · Network (extended)
U3505 Control Module Input Power B Circuit Low
Input power line B voltage below expected range. A communication loss with this module breaks any function relying on its data — diagnostic tools may show 'no response' and dependent modules can fall into limp mode.
Is it safe to drive with U3505?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyWeak battery or high supply resistance
- Less likelyGateway module routing CAN messages incorrectly
- Less likelyCAN terminating resistor (120 Ω) drifted out of spec
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Repair at a glance
- Difficulty
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.3–2 h
- Emissions test
- Usually unaffected
- Parts involved
- Module Power B, Power Wiring
Related codes
- U3501Control Module Input Power A Circuit Low
- U3509Control Module Input Power C Circuit Low
- U3502Control Module Input Power A Circuit High
- U3503Control Module Input Power A Circuit Intermittent/Erratic
- U3504Control Module Input Power B Circuit Range/Performance
- U3506Control Module Input Power B Circuit High
- U3507Control Module Input Power B Circuit Intermittent/Erratic
- U3508Control Module Input Power C Circuit Range/Performance
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.