P1698: No Communication With the Transmission Computer (Chrysler)
Severity: medium
What it means: P1698 is a Chrysler code meaning the engine computer isn't getting messages from the transmission computer (TCM) over the data network. Older cars call it 'No CCD message from TCM'. It can be a wiring fault, a low-voltage event, or a TCM problem.
Safe to drive? Drive carefully and get it checked. The transmission may go into limp mode with poor shifting.
Common symptoms
- Check engine light
- Possible limp mode or harsh shifting
- Other codes stored at the same time
Likely causes, ranked
- Wiring or connector problem on the data busShop
- Low battery voltage or poor groundsDIY
- Transmission computer (TCM) faultShop
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Vehicle-specific notes
- 1995–2000 Chrysler Cirrus: On Car Talk, a 1997 Cirrus that nearly stalled after cold starts had P1698 stored along with P0300, P0303 and P0455. Read the full answer · Source
DIY or shop?
DIY for checking the battery and grounds. Network diagnosis is a shop job.
Before you replace parts
- Read all stored codes and freeze-frame data, not just this one.
- Check your VIN for recalls, service bulletins and extended coverage.
- Inspect wiring and connectors for the related sensor or part before buying parts.
- Clear the code only after a repair, then confirm it stays off.
Safety / mechanic note
Verify with a mechanic. Limp mode can leave you with little power in traffic. A code points to a circuit or system, not always a specific part.
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