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P1501

Programmable Speedometer & Odometer Module Vehicle Speed Sensor Intermittent Circuit Failure.

  • Ford
  • Powertrain
  • Manufacturer code
  • Medium severity

How this code is built

P
SystemPowertrain
1
Defined byThe manufacturer
5
AreaVehicle speed, idle control and auxiliary inputs
01
FaultThe specific fault in that area

What it means

On Ford vehicles P1501 means the powertrain control module has seen an intermittent fault in the vehicle speed signal supplied through the programmable speedometer and odometer module (PSOM). The speed signal drops out, becomes erratic or disagrees with other inputs, such as engine speed and load, for short periods. The fault is not constant, so it may come and go and the exact signal path depends on the model and year.

Symptoms

  • Speedometer needle flickering, dropping to zero or reading wrongly
  • Odometer or trip meter not counting correctly
  • Engine management warning light on
  • Erratic idle or stalling when coming to a stop
  • Poor or harsh automatic gearshifts or no torque converter lock-up
  • Cruise control cutting out or not engaging

Possible causes

  • Faulty or contaminated vehicle speed sensor or its signal generatorlikely
  • Damaged, chafed or corroded wiring between the speed sensor, PSOM and PCMlikely
  • Loose, corroded or water-damaged connector at the speed sensor, PSOM or PCMlikely
  • Faulty programmable speedometer and odometer module or instrument clusterpossible
  • Damaged drive gear or tone wheel in the gearbox or final drive, or a wheel speed signal fault on models that use itpossible
  • Electrical interference or poor earth connection affecting the signalpossible
  • Internal fault in the powertrain control modulerare

How to diagnose

  1. Read all stored and pending codes and note the freeze frame data, including vehicle speed, engine speed and load when the fault set
  2. Check for related codes in the gearbox, ABS and instrument cluster modules, as these may point to a shared signal fault
  3. Compare the speedometer reading with live vehicle speed data from the PCM on a road test and watch for dropouts
  4. Inspect the speed sensor, its wiring and connectors for damage, oil contamination, corrosion and loose pins, flexing the harness while watching live data
  5. Check the sensor for metallic debris and the drive gear or tone wheel for damage, as access depends on the model
  6. Check the sensor supply voltage, signal and earth against the manufacturer's wiring diagram for the specific model
  7. Check the integrity of the earth connections for the PCM and instrument cluster
  8. Test the PSOM or cluster signal output with an oscilloscope, following the model-specific procedure

How to fix

  • Replace the vehicle speed sensor if its signal drops out or it is contaminated or damaged
  • Repair or replace damaged wiring and clean or replace corroded connectors and terminals
  • Repair any poor earth connections
  • Replace or repair the programmable speedometer and odometer module or cluster if it is proven faulty, and note that some units need programming to the vehicle
  • Replace a damaged drive gear or tone wheel
  • Replace the PCM only once all inputs and wiring are proven good, then program it as required

Can I keep driving?

Medium severity

The car can usually be driven for a short time, but fix it soon because the speed signal may drop out and cause stalling, poor shifting or an inaccurate speedometer. Take extra care if the speedometer or gearbox behaviour becomes unreliable.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.

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