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.
2003 Saturn Ion 1 AutomaticFACTORY OEM SERVICE PROCEDURE
Data Link Communication DTCS
DATA LINK COMMUNICATION DIAGNOSTIC TROUBLE CODE (DTC) LIST
| DTC | Description |
|---|---|
| DTC U1000 and U1255 | Class 2 Data Link |
| DTC U1001 To U1254 | Module U1XXX Communication |
| DTC U1300, U1301, or U1305 | Class 2 Data Link |
| DTC U2100 | CAN Bus Error With Engine Control System |
| DTC U2103 or U2104 | Fewer Controllers On Bus Than Programmed, Or Controller Area Network (CAN) Bus Reset Counter Overrun |
| DTC U2105 | Lost Communications With Engine Control System |
| DTC U2106 | Lost Communications With Transmission Control System |
Factory Service Tools
Use the Manual With the Right Hardware
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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.
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