Engine-Codes - GMC - P1229 GMC

P1229 GMC Code - Injector 3 Output Circuit

- Code Popularity: 5,762 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 2/3
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What are the Possible Causes of the DTC P1229 GMC?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Faulty Fuel Injector 3
  • Fuel Injector 3 harness is open or shorted
  • Fuel Injector 3 circuit poor electrical connection
  • Faulty Fuel Injection Control Module (FICM)
  • Faulty Engine Control Module (ECM)

Code Tech Notes

If only 1 fuel injector Control circuit Diagnostic Trouble Code (DTC) is set, an open circuit or poor connection is the most likely cause. If groups of 4 fuel injector Control circuit DTCs are set, suspect a short to ground. Cylinder groups are 2, 3, 5, 8 or 1, 4, 6, 7. More than 4 fuel injector Control circuit DTCs set indicate short to voltage on fuel injector Control circuit is the most likely cause.

There is a factory service bulletin for the following models:

2004 GMC Sierra
2005 GMC Sierra
2004 GMC Topkick
2005 GMC Topkick
2004-2005 GMC Sierra, Topkick Factory Service Bulletin OBDII Code P1229

⚠ Does your GMC have Safety Recalls? → Check here

How to Fix the DTC P1229 GMC?

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.

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What is the Cost to Diagnose the Code?

Labor: 1.0

The cost to diagnose the P1229 GMC 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.

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)
  • Engine Misfire
  • Rough Running

What Does the P1229 GMC Code Mean?

The Engine Control Module (ECM) enables the appropriate fuel injector on the compression stroke for each cylinder. The ECM controls the Fuel Injection Control Module (FICM) by grounding the control circuit via a solid state device called a driver. The ECM monitors the state of the driver. If the ECM detects an incorrect voltage for the commanded state of an injector driver, Diagnostic Trouble Code (DTC) P1223, P1226, P1229, P1232, P1235, P1238, P1241, or P1244 will set.

P1229 GMC Code - Injector 3 Output Circuit

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