OBD Guide
ENFRDEESPT

P0647

A/C Clutch Relay Control Circuit High

P0647 is an OBD-II diagnostic trouble code meaning: A/C Clutch Relay Control Circuit High. Common causes: short circuit of the relay control wire to the power source, relay fault (contacts closed). Estimated repair cost: $3–278.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$3–278 (est.)

Symptoms

  • Check Engine light comes on
  • The air conditioner can be constantly on
  • Increased load on the engine (reduced power)
  • The air conditioner does not respond to the off button
  • The compressor runs constantly, causing noise

Causes

  • Short circuit of the relay control wire to the power source
  • Relay fault (contacts closed)
  • Wiring harness insulation damage
  • ECU output stage malfunction (no ground)
  • Incorrect connection after repair

How to Fix

  1. Check the voltage at the relay control contact with the air conditioner turned off (should be about 0 V)
  2. Replace A/C Relay
  3. Check the control wire from the ECU to the relay for a short to positive
  4. Inspect the wiring harness for damaged insulation
  5. Check the operation of the ECU output stage (diagnostics on the bench)
  6. If necessary, repair or replace the ECU

Related codes

P0645P0646P0530P0533

Error P0647 by Vehicle Brand

AcuraAudiBAICBMWBYDBuickCadillacChanganCheryChevroletChryslerCitroenDodgeDongfengExeedFAWFordForthingFotonGACGMGMCGeelyGreat WallHavalHondaHongqiHyundaiInfinitiJACJaecooJaguarJeepJetourKaiyiKiaLadaLexusLi AutoLifanLincolnLivanMazdaMercedes-BenzMercuryMitsubishiNIONissanOldsmobileOmodaOpelPeugeotPlymouthPontiacRenaultSWMSaturnSkodaSkywellSubaruSuzukiTankToyotaVolkswagenVolvoVoyahXPengZeekrZotye

FAQ

What does the P0647 code mean?

P0647 is an OBD-II diagnostic trouble code that indicates: A/C Clutch Relay Control Circuit High

What causes a P0647 error code?

The most common causes of P0647 include: Short circuit of the relay control wire to the power source; Relay fault (contacts closed); Wiring harness insulation damage; ECU output stage malfunction (no ground).

How do I fix a P0647 diagnostic trouble code?

To fix P0647: Check the voltage at the relay control contact with the air conditioner turned off (should be about 0 V). Replace A/C Relay. Check the control wire from the ECU to the relay for a short to positive. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P0647?

Limited driving only, diagnose soon

How much does it cost to fix P0647?

The estimated repair cost for P0647 is $3–278. Actual cost depends on your vehicle, location, and labor rates.

FRDEESPT

See also: Russian version · NationStat