Engine-Codes - Suzuki - P0621 Suzuki

P0621 Suzuki Code - Generator Lamp L Control Circuit Malfunction

- Code Popularity: 3,364 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 3/3
Table of contents
ChatAC AutoCodes.com AI Chat

What are the Possible Causes of the DTC P0621 Suzuki?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Battery charge
  • Faulty Generator
  • Generator harness is open or shorted
  • Generator circuit poor electrical connection
  • Engine Control Module (ECM) controlled generator
  • Faulty ECM

Code Tech Notes

The ECM/PCM is detecting a high turn-on voltage at times. Possible causes could be the alternator or the ECM/PCM.

⚠ Does your Suzuki have Safety Recalls? → Check here

How to Fix the DTC P0621 Suzuki?

Check the 'Possible Causes' listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

Search for P0621 Suzuki Questions and Answers: Search here →

What is the Cost to Diagnose the Code?

Labor: 1.0

The cost to diagnose the P0621 Suzuki code is 1.0 hour of labor. The diagnosis time and labor rates at auto repair shops vary depending on the location, make and model of the vehicle, and even the engine type. Most auto repair shops charge between $75 and $150 per hour.

When is the Code Detected?

The Engine Control Module (ECM) has fault detection circuitry which monitors the state of the generator turn on signal circuit. If the fault detection circuit senses a voltage other than what is expected, this P0621 code will set. The voltage regulator also contains fault detection circuitry. If the regulator detects a problem, the regulator will ground the generator turn on signal circuit, pulling the voltage low. This also causes the ECM to set the P0621 code.

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)

What Does the P0621 Suzuki Code Mean?

The Engine Control Module (ECM) uses the generator turn on signal circuit to control the generator. A high side driver within the ECM allows the ECM to turn the generator ON and OFF. When Generator operation is desired, the ECM sends a 5 volt signal to the voltage regulator via the generator turn on signal circuit. This causes the voltage regulator to begin controlling the generator field circuit. Once the Generator is enabled by the ECM, the voltage regulator controls generator output independently of the ECM. Under certain operating conditions, the ECM can turn Off the generator by turning Off the 5 volt signal on the generator turn on signal circuit.
P0621 Suzuki Code - Generator Lamp L Control Circuit Malfunction

Need more Information on the Code?

Need more information on how to fix the P0621 Suzuki code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0621 Suzuki code diagnosed by a professional: Find a repair shop in your area