Mechanics

FAILED EMISSIONS TEST

1998 Dodge Caravan

1998 Dodge Caravan 6 cyl Two Wheel Drive Automatic 205600 miles

I recently took my van for emissions testing and failed due to service engine soon light on. The trouble code they say is present is P1698. How can I pass emmisions test for as cheap as possible seeing as there is over 205,000 miles on the van.
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Johnloerop
June 1, 2010.



Hi Johnloerop, Welcome to 2carpros and TY for the donation

Dunno how cheap the repair could be but below will help you diagnose the problem and go from there.

1698 is a communication failure code from the PCM to the TCM. Here are the steps to testing the circuit.

TESTS W/CODES - 3.3L -1997 Dodge Grand Caravan Page 1 of 2

TEST TC-96A - NO CCD MESSAGES FROM TRANSMISSION CONTROL MODULE (TCM)

NOTE: For connector terminal ID, see the CONNECTOR
IDENTIFICATION DIRECTORY. For wiring diagram, see WIRING
DIAGRAMS - 3.3L article.

1. Connect scan tool to data link connector. Turn ignition on.
Select TRANSMISSION and then 41TE on scan tool. Scan tool
automatically performs a self-test on the CCD bus. If scan tool
displays BUS OPERATIONAL, go to next step. If scan tool displays
does not display BUS OPERATIONAL and a CCD bus failure message
such as SHORT TO BATTERY or SHORT TO GROUND is displayed, see
appropriate VEHICLE COMMUNICATIONS article in ACCESSORIES & EQUIPMENT section.
2. Select ENGINE MODULE on scan tool. Using scan tool, clear
Diagnostic Trouble Codes (DTCs) from Powertrain Control Module
(PCM). Raise and support vehicle so all wheels are off the
ground.
3. Start engine and allow engine to idle. Place shift lever in
Drive, allowing front wheels to rotate for one minute. Apply
brakes. Place shift lever in Park. Using scan tool, check for
stored DTCs.
4. If scan tool displays NO CCD MESSAGE FROM TCM, go to step 8). If
scan tool does not display NO CCD MESSAGE FROM TCM, go to next
step.
5. Conditions required to set DTC are not present at this time. The
PCM and TCM communicate messages across the CCD bus, as
information from either module is needed to operate their
respective systems. DTC may be stored in PCM when no CCD bus
messages are received from TCM for 10 seconds. Possible causes
are: open circuit in CCD bus, TCM is not powered up, defective
TCM or defective PCM.
6. Check for defective wiring or connections at PCM and TCM. The
PCM is located between driver's side front fender and power
distribution center, near battery. The TCM is located on
passenger's side front corner of engine compartment, on inner
fender, near windshield washer reservoir. See Fig. 50.

Fig. 50: Locating Transmission Control Module (TCM)

7. If wiring or connectors are damaged, repair as necessary.
Perform TEST VER-2A. If wiring and connectors are not damaged,
see INACTIVE TROUBLE CODE CONDITION. Perform TEST VER-2A.
8. Ensure ignition is off. Disconnect connectors at PCM and TCM.
The PCM is located between driver's side front fender and power
distribution center, near battery. The TCM is located on
passenger's side front corner of engine compartment, on inner fender, near windshield washer reservoir. See Fig. 50.
9. Using ohmmeter, check resistance between PCM connector terminal
No. 59 (Violet/Brown wire) and TCM connector terminal No. 43
(Violet/Brown wire). If resistance is 5 ohms or more, repair
open circuit in Violet/Brown wire between PCM and TCM. Perform
TEST VER-2A. If resistance is less than 5 ohms, go to next step.
10. Using ohmmeter, check resistance between PCM connector terminal
No. 60 (White/Black wire) and TCM connector terminal No. 4
(White/Black wire). If resistance is 5 ohms or more, repair open
circuit in White/Black wire between PCM and TCM. Perform TEST
VER-2A. If resistance is less than 5 ohms, go to next step.
11. Reinstall connectors on PCM and TCM. Turn ignition on. Select
TRANSMISSION and then 41TE on scan tool. If scan tool displays
NO RESPONSE, replace TCM. Perform TEST VER-2A. If scan tool does
not display NO RESPONSE, replace PCM. Perform TEST VER-2A.

Rasmataz
Jun 1, 2010.