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P1358

Ignition Diagnostic Monitor Signal Out of Self-Test Range.

  • Lincoln
  • Powertrain
  • Manufacturer code
  • Medium severity

How this code is built

P
SystemPowertrain
1
Defined byThe manufacturer
3
AreaIgnition system or misfire
58
FaultThe specific fault in that area

What it means

On Lincoln (Ford group) models, P1358 means the engine control module saw the ignition diagnostic monitor (IDM) signal outside its expected range during the self-test. The IDM signal is a feedback pulse from the ignition system that tells the module the coil primary circuit is firing. If that signal is missing, stuck or erratic, the module cannot confirm that ignition is working properly and sets the code.

Symptoms

  • Engine misfire or rough running
  • Hesitation or poor acceleration
  • Hard starting or extended cranking
  • Malfunction indicator lamp on
  • Poor fuel economy
  • Occasional stalling

Possible causes

  • Wiring fault in the IDM signal circuit, such as a chafed, open or shorted wire to the modulelikely
  • Corroded, loose or damaged connector at the ignition module, coil pack or engine control modulelikely
  • Faulty ignition coil, coil pack or ignition control module, depending on the engine fittedlikely
  • Worn spark plugs or damaged plug leads increasing the load on the ignition systempossible
  • Low battery voltage or poor power and earth supply to the ignition systempossible
  • Faulty engine control modulerare

How to diagnose

  1. Read all stored and pending codes and note the freeze frame data, paying attention to any misfire codes stored alongside P1358
  2. Check the battery condition and charging voltage, as low voltage can upset ignition signals
  3. Inspect the ignition wiring and connectors for chafing, heat damage, corrosion and loose pins, especially around the coil pack and ignition module
  4. Inspect spark plugs and leads for wear, cracks, carbon tracking or incorrect gap
  5. Check the power and earth supplies to the ignition coils and ignition module against the wiring diagram for the specific model and engine
  6. Test the IDM signal circuit for continuity, short to earth and short to voltage, following the manufacturer procedure for that engine
  7. Test the coils and ignition module using the specified resistance values or a scope pattern for that engine
  8. Clear the code, run the self-test again and road test to see whether it returns

How to fix

  • Repair or replace damaged wiring in the IDM signal circuit
  • Clean or replace corroded or loose connectors and terminals
  • Replace the faulty ignition coil, coil pack or ignition module once testing confirms it
  • Replace worn spark plugs and defective leads with the correct specification parts
  • Restore a healthy battery and sound power and earth connections
  • Replace or update the engine control module only after all other causes are ruled out and the manufacturer procedure calls for it

Can I keep driving?

Medium severity

The car can usually be driven short distances, but get it checked soon. A continuing misfire can overheat and damage the catalytic converter, so avoid hard acceleration and stop driving if the engine runs very roughly or the warning light flashes.

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

This code for other makes

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