OBD Guide

P173B

CAN Engine Coolant Temperature Invalid

P173B is an OBD-II diagnostic trouble code meaning: CAN Engine Coolant Temperature Invalid. Common causes: coolant temperature sensor malfunction, open or short circuit in the sensor circuit. Estimated repair cost: $6–28.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$6–28 (est.)

Symptoms

  • Incorrect temperature readings on the dashboard
  • Engine overheating
  • Unstable cooling fan operation
  • Increased fuel consumption
  • Check Engine Light Illuminates

Causes

  • Coolant temperature sensor malfunction
  • Open or short circuit in the sensor circuit
  • Problems with the CAN bus
  • Engine control unit malfunction
  • Corroded contacts or poor connection

How to Fix

  1. Check the temperature sensor readings using a diagnostic scanner
  2. Inspect the wiring and connectors of the temperature sensor
  3. Check the resistance of the temperature sensor at different temperatures
  4. Check the integrity of the CAN bus
  5. If necessary, replace the coolant temperature sensor

Related codes

FAQ

What does the P173B code mean?

P173B is an OBD-II diagnostic trouble code that indicates: CAN Engine Coolant Temperature Invalid

What causes a P173B error code?

The most common causes of P173B include: Coolant temperature sensor malfunction; Open or short circuit in the sensor circuit; Problems with the CAN bus; Engine control unit malfunction.

How do I fix a P173B diagnostic trouble code?

To fix P173B: Check the temperature sensor readings using a diagnostic scanner. Inspect the wiring and connectors of the temperature sensor. Check the resistance of the temperature sensor at different temperatures. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P173B?

Limited driving only, diagnose soon

How much does it cost to fix P173B?

The estimated repair cost for P173B is $6–28. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat