OBD Guide
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P1666

Cruise Control Module Internal

P1666 is an OBD-II diagnostic trouble code meaning: Cruise Control Module Internal. Common causes: internal malfunction of the cruise control module, module power problems. Estimated repair cost: $56–167.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$56–167 (est.)

Symptoms

  • Cruise control won't turn on
  • Cruise control turns off spontaneously
  • Cannot set cruise control speed
  • Check Engine light comes on
  • The cruise control system does not respond to commands

Causes

  • Internal malfunction of the cruise control module
  • Module power problems
  • Short circuit in the module circuit
  • Wiring harness damage
  • Software error in the module

How to Fix

  1. Check cruise control system fuses and relays
  2. Check the integrity of the wiring harness to the module
  3. Check the module supply voltage
  4. Flash or update module software
  5. Replace the cruise control module if necessary

Related codes

P1665P1667

Error P1666 by Vehicle Brand

BuickCadillacChevroletGMGMCOldsmobileSaturn

FAQ

What does the P1666 code mean?

P1666 is an OBD-II diagnostic trouble code that indicates: Cruise Control Module Internal

What causes a P1666 error code?

The most common causes of P1666 include: Internal malfunction of the cruise control module; Module power problems; Short circuit in the module circuit; Wiring harness damage.

How do I fix a P1666 diagnostic trouble code?

To fix P1666: Check cruise control system fuses and relays. Check the integrity of the wiring harness to the module. Check the module supply voltage. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P1666?

Yes, but get it checked soon

How much does it cost to fix P1666?

The estimated repair cost for P1666 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

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See also: Russian version · NationStat