Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Intermittent Malfunction Indicator Lamp (Mil) Illuminated, DTC P2138 With Reduced Engine Power (Repair Instrument Panel (IP) To Body Harness Connector) (07-06-04-019F)
Reference number: 07-06-04-019F
Supersedes refnos: 07-06-04-019, 07-06-04-019A, 07-06-04-019B, 07-06-04-019D, 07-06-04-019E
INTERMITTENT MALFUNCTION INDICATOR LAMP (MIL) ILLUMINATED, DTC P2138 WITH REDUCED ENGINE POWER (REPAIR INSTRUMENT PANEL (IP) TO BODY HARNESS CONNECTOR)
TECHNICAL SERVICE BULLETIN
| Affected Model(s): | 2018 and Prior GM Passenger Cars and Light Duty Trucks |
| Attention: | For 2014 Model Year ATS, refer to the latest version of Product Emission Bulletin 14176 before proceeding with this Bulletin. This Bulletin also applies to any of the above models that may be Export vehicles. |
| Supercedes: | This Bulletin has been revised to add the 2016-2018 Model Years. Please discard Corporate Bulletin Number 07-06-04-019E. |
CONDITION
- Some customers may comment on an intermittent malfunction indicator lamp (MIL) being Illuminated with a message or an indicator that displays Reduced Engine Power.
- The technician may observe on a scan tool DTC P2138 - Accelerator Pedal Position (APP) Sensor 1-2 Correlation set as Current or in History.
CAUSE
This condition may be caused by water intrusion into the instrument panel (IP) to body harness connector, which carries the APP sensor signals to the ECM/PCM. This water intrusion results in a voltage difference between APP Sensor 1 and APP Sensor 2 that exceeds a predetermined value for more than a calibrated period of time, setting P2138.
CORRECTION
Aftermarket equipment can generate DTC P2138 and/or other DTCs.
- Verify that aftermarket equipment is not electrically connected to any of the APP sensor signal or low reference circuits or to any other ECM/PCM 5V reference or low reference circuits. Refer to Checking Aftermarket Accessories in SI.
- Perform the Diagnostic System Check - Vehicle.
- If any 5V reference DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle.
- If any 5V reference DTCs are not set, proceed to Step 3.
- Locate the IP to body harness connector, which may be located in and around the left hand kick panel area or inside the IP. Depending on the vehicle and model year, refer to Wiring Systems or Power and Signal Distribution in SI.NOTE:
Some examples of potential water leaks are: A-pillar seals, sunroof drain lines (if equipped) and windshield/cowl sealing.
- Inspect for a water leak in the area. If necessary use a water hose to determine the source of the leak. Refer to General Information > Water Leaks in SI.
- If a water leak is observed, repair as necessary. Verify the effectiveness of the repair.
- Inspect the IP to body harness connector terminals for corrosion and debris. Refer to Testing for Intermittent Conditions and Poor Connections in SI.
- If any corrosion and/or debris is observed, repair as necessary.
- After completing the repair, verify the proper operation of the system. Depending on the vehicle and model year, perform the Diagnostic Repair Verification procedure or refer to Diagnostic Trouble Code (DTC) List - Vehicle in SI.
WARRANTY INFORMATION
For vehicles repaired under warranty, use the appropriate labor operation for the source of the water leak
| Labor Operation | Description | Labor Time |
|---|---|---|
| 0560032 | Body Joint Resealing | Use Published Labor Operation Time |
| 0560052 | Plenum Panel Resealing | |
| 0560072 | Windshield Resealing | |
| Note: Time for removal of necessary components to gain access to the leak and connector repair must be submitted as Other Labor Hours and have appropriate authorization. | ||
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.