P1698 On Dodge and Chrysler, the engine computer stopped receiving messages from the transmission computer on the vehicle data bus

Dodge/Chrysler no data bus message from the transmission control module (TCM)

Severity not verified — if the car runs badly, have it inspected

The sources define the code as lost communication with the transmission computer but none say how serious it is. Owners report it alongside a blank instrument cluster, so the cause could be a data bus fault rather than the transmission itself.

Source: how we rate severity

P1698 in short

On Dodge and Chrysler, P1698 means the engine computer is not getting data bus messages from the transmission computer. On older vans and trucks, owners report it with a blank instrument cluster and several warning lights. A bus wiring or module fault is likely; have it scanned for other communication codes.

Modern vehicles pass messages between computers on a data bus. The engine computer expects regular messages from the transmission computer. When they stop, it sets P1698.

The code does not say which side failed. A dealer scan on a 2002 Ram read it as "No CCD, J1850 message from TCM" and cleared it. On 1997 and 1999 Grand Caravans, owners report the code with a blank instrument cluster, ABS and airbag lights and dead door locks, which points to a communication fault shared by several modules.

Chrysler also lists P1698 among false codes in two 2003 bulletins, one for a no-start that clears when the key is cycled. Those bulletins list the code without defining it, so they are context only.

Pick your make

P1698 is a manufacturer-specific code: its meaning depends on who built the car.

Other makes: meaning not verified. Check with a scan tool that reads manufacturer definitions.

Most likely causes

These are general causes for this code across vehicles. None is specific to one make or model.

  1. Data bus wiring, connector or cluster connection fault

    Possible — needs testing
    Why it ranks here
    Owners with 1997-1999 Grand Caravans report P1698 with a cluster that goes blank and other modules dropping out, and one attributes it to faulty connections in the cluster. This is owner opinion, so it is a lead to test rather than a proven cause.
    What would change this
    Rises if other modules also show lost communication or the cluster goes dark at the same time. Falls if only the transmission computer is silent.
    How to test the transmission control module (tcm)

  2. Transmission control module not sending (power, ground or internal fault)

    Possible — needs testing
    Why it ranks here
    The definition itself is that the transmission computer sends no message. A scan on a 2002 Ram was cleared and road-tested, which suggests the fault was intermittent there.
    What would change this
    Rises if the transmission computer will not communicate with a scan tool. Falls if it answers normally.
    How to test the transmission control module (tcm)

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Scan every module for stored codes, not just the engine computer. Note whether the transmission computer, ABS, airbag and cluster respond.

    Low riskTool: scan tool that reads Chrysler body and chassis modules

Symptoms

  • Check engine light with P1698 and no other code
  • Instrument cluster goes blank or gauges drop to zero for a few minutes
  • ABS and airbag lights come on together with the cluster fault

How to fix

Parts and cost context

  • Transmission control module (TCM):Replacing the module is a last step; prove the bus wiring and power supply first. Labour varies; get a quote.

Labor varies by vehicle and shop; get a quote before you approve a repair.

Compare used part prices on PartPriceGuide

On your vehicle

Dodge

  • 1997–1999 · Grand Caravan

    Supported by vehicle data

    Owners of 1997 and 1999 Grand Caravans report P1698 with a blank instrument cluster and other warning lights.

  • 1802603A (dodge)Status unverified

    No start with false DTCs including P1698

    2003grand-caravan · NHTSA 10003985

    Same bulletin for the Dodge Caravan; the NHTSA record names Caravan, and the slug is the closest model listed.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

No curated relationships for P1698 yet.

All Module network (CAN bus) communication codes

Sources and review

  1. P1698 trouble code definition by make — troublecodes.net
  2. NHTSA complaint ODI 10010135: 2002 Dodge Ram Club Cab, P1698 — NHTSA Office of Defects Investigation (owner complaint)
  3. NHTSA complaint ODI 10155928: 1997 Dodge Grand Caravan, P1698 — NHTSA Office of Defects Investigation (owner complaint)
  4. NHTSA complaint ODI 10607487: 1999 Dodge Grand Caravan, P1698 — NHTSA Office of Defects Investigation (owner complaint)
Last reviewed
Written by
Saurabh K.
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