OBD Guide

P1A79

Starter/Generator Control Module Coolant Temperature Sensor 3 Circuit Low Voltage

P1A79 is an OBD-II diagnostic trouble code meaning: Starter/Generator Control Module Coolant Temperature Sensor 3 Circuit Low Voltage. Common causes: coolant temperature sensor malfunction, open or short circuit in the electrical circuit. Estimated repair cost: $17–56.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$17–56 (est.)

Symptoms

  • Check Engine light comes on
  • Deterioration of the starter/generator system
  • Battery charging problems
  • Reduced hybrid system efficiency (if applicable)
  • Unstable engine operation at idle

Causes

  • Coolant temperature sensor malfunction
  • Open or short circuit in the electrical circuit
  • Poor contact in sensor connectors
  • Starter/Generator Control Module Malfunction
  • Circuit Grounding Problems

How to Fix

  1. Check the integrity and resistance of the temperature sensor
  2. Inspect the electrical circuit for damage
  3. Check the quality of contacts in the connectors
  4. Scan the control module for other errors
  5. If necessary, replace the coolant temperature sensor

Related codes

FAQ

What does the P1A79 code mean?

P1A79 is an OBD-II diagnostic trouble code that indicates: Starter/Generator Control Module Coolant Temperature Sensor 3 Circuit Low Voltage

What causes a P1A79 error code?

The most common causes of P1A79 include: Coolant temperature sensor malfunction; Open or short circuit in the electrical circuit; Poor contact in sensor connectors; Starter/Generator Control Module Malfunction.

How do I fix a P1A79 diagnostic trouble code?

To fix P1A79: Check the integrity and resistance of the temperature sensor. Inspect the electrical circuit for damage. Check the quality of contacts in the connectors. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P1A79?

Yes, but get it checked soon

How much does it cost to fix P1A79?

The estimated repair cost for P1A79 is $17–56. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat