What causes P1105 on a Ford?

Failed upper alternator Open field control circuit to the upper unit Seized upper alternator bearing Corroded charge cable connections PCM field driver fault

How do I fix P1105 on a Ford?

Load-test each alternator independently Check field control voltage at the upper unit Inspect belts, bearings and cable ends Verify grounds for both units Replace the failed alternator after circuit checks

P1105 Dual Alternator Upper Malfunction

Q: What does P1105 mean on a Ford?

P1105 — Dual Alternator Upper Malfunction. Applies to Super Duty and E-Series with dual alternator packages.

Category: Powertrain - Computer and Auxiliary Controls
Severity: Check Engine Light
Applies to: Super Duty and E-Series with dual alternator packages

What does P1105 mean on a Ford?

P1105 — Dual Alternator Upper Malfunction. This Ford-enhanced code applies to Super Duty and E-Series with dual alternator packages.

Common causes of P1105

Failed upper alternator
Open field control circuit to the upper unit
Seized upper alternator bearing
Corroded charge cable connections
PCM field driver fault

How to fix P1105

Load-test each alternator independently
Check field control voltage at the upper unit
Inspect belts, bearings and cable ends
Verify grounds for both units
Replace the failed alternator after circuit checks