P1626

Code

LINCOLN P — Powertrain

Voltage to Vehicle Load Control Module Circuit Not Detected

Brand: LINCOLN

Type: P — Powertrain

Views: UK: 20 EN: 57 RU: 28

AI status

Completed

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Page language: EN

Causes

Blown fuse or fusible link supplying the Vehicle Load Control Module
Open or shorted power feed wiring between the battery/fusebox and the VLCM
Loose, corroded, or disconnected connector at the VLCM
Weak or dead battery or poor battery terminals/connection
Failed VLCM (internal power supply or connector fault)
Faulty ignition / accessory relay or PCM-supplied enable circuit

Symptoms

DTC P1626 stored in ECM/PCM and possibly other modules
Certain electrical loads (interior lights, HVAC blower, pumps, relays) do not operate or are intermittent
Related body/control module warning lights or malfunctions
Vehicle may show parasitic battery drain or not retain accessory power
No obvious fault with sensors but controlled loads do not switch

What to check

Scan for stored and pending codes and read freeze frame/live data from ECM/PCM
Visually inspect battery terminals, cables and charging system; verify battery state of charge
Inspect relevant fuses, fusible links and relays for the VLCM power feed — check both in-cab and under-hood boxes
Visually inspect the VLCM connector and wiring harness for damage, corrosion, pin push-out, or moisture
Check ground connections for the VLCM and nearby chassis grounds for tightness and corrosion
Backprobe the VLCM power pin with key ON and compare to battery voltage

Signal parameters

Battery voltage (engine off, fully charged): ~12.4–12.8 V
Charging voltage (engine running): ~13.5–14.8 V
Expected VLCM power feed with KEY ON: within ~0.2–0.5 V of battery voltage (should be battery voltage if unswitched feed)
Expected VLCM ground resistance to chassis:
Open-circuit or

Diagnostic algorithm

Verify the code: connect a scan tool, record P1626 and any related codes, note freeze frame data and any relevant PID values.
Battery & charging check: measure battery voltage (key off and key on) and charging system output with engine running. Repair as needed.
Fuse & relay check: locate VLCM-related fuses/fusible links and relays. Visually inspect and measure for continuity/power. Replace blown fuses and retest.
Visual/connector inspection: disconnect battery negative, inspect VLCM connector pins for corrosion, bent pins, or pushed-out terminals. Repair or replace connector as necessary.
Backprobe power feed: reconnect battery, backprobe the VLCM power input pin with key ON. Compare voltage to battery. If no voltage, trace power feed toward the fuse box and battery.
Wiring continuity: with battery disconnected, check continuity/resistance from VLCM power pin to the corresponding fuse/battery terminal. Repair open or high-resistance circuits.
Ground verification: check continuity from VLCM ground pin to chassis and battery negative. Clean and tighten grounds if high resistance found.
Check supply source control: if the supply is controlled by a relay or the PCM, verify that relay/PCM output is commanding power. Test the relay and check for control voltage on the relay coil or module enable pin.
Repair wiring/connectors or replace defective fuse/relay. If wiring repaired, protect harness with grommet/loom, secure routing and reassemble.
If supply wiring and connectors are good and correct voltage is present but code persists, test or replace the Vehicle Load Control Module. Reprogram if required by manufacturer.
Clear DTCs, run the vehicle and re-scan. Confirm the code does not return and that associated loads function correctly.

Likely causes

Blown VLCM fuse or fusible link
Corroded or disconnected connector at the VLCM or fuse block
Open/broken power feed or chafed wiring harness to the VLCM
Battery voltage low or poor battery terminal connection
Failed Vehicle Load Control Module
Bad ground at module mounting point

Fault status

⚠️ Status

P1626 — Voltage to Vehicle Load Control Module circuit not detected (No power on VLCM feed)

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-2.5 hours

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P1626 — Voltage to Vehicle Load Control Module Circuit Not Detected