OBD Guide
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P04D5

Exhaust Brake Input Circuit Low

P04D5 is an OBD-II diagnostic trouble code meaning: Exhaust Brake Input Circuit Low. Common causes: broken wire in engine brake input circuit, short circuit to ground in signal circuit. Estimated repair cost: $22–100.

Severity
⚠️ Medium
Can you drive?
Do not drive — repair immediately
Approx. repair cost
$22–100 (est.)

Symptoms

  • Engine brake does not engage when activated
  • Malfunction indicator light (Check Engine or MIL) is on
  • Reduced braking efficiency on descents
  • Possible associated error code P04D6

Causes

  • Broken wire in engine brake input circuit
  • Short circuit to ground in signal circuit
  • Faulty engine brake switch
  • Damage to the connector or contacts
  • Control module malfunction

How to Fix

  1. Read error codes with scanner and record freeze frame data
  2. Find the switch and input circuit of the engine brake according to the diagram
  3. Check the voltage at the circuit input with a multimeter with the brake on and off
  4. Check the integrity of the wire from the switch to the computer
  5. Inspect connectors for damage and oxidation
  6. Replace the switch if it is faulty
  7. Repair open or short circuit in wiring
  8. Reset the error and check the system operation

Related codes

P04D6P04D7P04D8

Error P04D5 by Vehicle Brand

AcuraAudiBAICBMWBYDBuickCadillacChanganCheryChevroletChryslerCitroenDodgeDongfengExeedFAWFordForthingFotonGACGMGMCGeelyGreat WallHavalHondaHongqiHyundaiInfinitiJACJaecooJaguarJeepJetourKaiyiKiaLadaLexusLi AutoLifanLincolnLivanMazdaMercedes-BenzMercuryMitsubishiNIONissanOldsmobileOmodaOpelPeugeotPlymouthPontiacRenaultSWMSaturnSkodaSkywellSubaruSuzukiTankToyotaVolkswagenVolvoVoyahXPengZeekrZotye

FAQ

What does the P04D5 code mean?

P04D5 is an OBD-II diagnostic trouble code that indicates: Exhaust Brake Input Circuit Low

What causes a P04D5 error code?

The most common causes of P04D5 include: Broken wire in engine brake input circuit; Short circuit to ground in signal circuit; Faulty engine brake switch; Damage to the connector or contacts.

How do I fix a P04D5 diagnostic trouble code?

To fix P04D5: Read error codes with scanner and record freeze frame data. Find the switch and input circuit of the engine brake according to the diagram. Check the voltage at the circuit input with a multimeter with the brake on and off. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P04D5?

Do not drive — repair immediately

How much does it cost to fix P04D5?

The estimated repair cost for P04D5 is $22–100. Actual cost depends on your vehicle, location, and labor rates.

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See also: Russian version · NationStat