← Back to list

2003 Dodge Caravan P0700 Code: Diagnosis, TCM Issues, and Fix

Model: 2003 dodge caravan Fault Code: P0700 Posted: 2014-07-02 17:05

My 2003 Dodge Caravan recently developed a check engine light issue. After scanning at AutoZone, I received codes P0700, P1698, and P0500. The vehicle will only move up to 50 mph without forced acceleration. I replaced both the input and output speed sensors and installed a remanufactured TCM from All Computer Resources, Inc. However, this introduced new problems — the check engine light returned, and code P0700 persists. I disconnected the negative battery terminal and TCM harness for over an hour before reconnecting them. After restarting, the check engine light came back on with P0700 still present. All Computer Resources advised that the issue must be with my vehicle, not the TCM. I'm now seeking advice: Is a TCM replacement a last resort? What specific wiring or electrical checks should I perform before replacing parts again? Can AutoZone's OBD2 scanners reliably detect transmission-specific codes like P0700? I've ruled out aftermarket accessories, remote starters, or alarms. The vehicle is stock. Any insights on diagnosing the root cause of P0700 in a 2003 Dodge Caravan would be greatly appreciated.

Related fault codes

P0700

Comments (13)

Anonymous 2014-07-02 17:37

Replacing a TCM should only be done after thorough troubleshooting — it's not a typical fix. Are you still seeing P0700, or do codes like P0500 and P1698 remain? The vehicle is stock with no electrical modifications?

Anonymous 2014-07-02 21:13

Only P0700 remains now. The other codes disappeared after replacing the speed sensors and installing a new TCM. No aftermarket electronics or accessories are present.

Anonymous 2014-07-03 07:33

AutoZone's OBD2 scanners use generic tools that may not detect specific transmission control module (TCM) fault codes. A dedicated scan tool capable of reading TCM-specific data is required for accurate diagnosis.

Anonymous 2014-07-03 12:11

I used the ignition key trick — turning the key three times — and P0700 appeared. I'm considering visiting a Dodge dealer to have it checked, though it's expensive. Any advice on what to expect? Thanks for all the input — I'll update everyone once I know more.

Anonymous 2014-07-03 12:51

The 'key trick' method does not reliably retrieve all fault codes. AutoZone scanners are better than key cycling but still incomplete. A possible cause could be that the TCM is not receiving power at all.

Anonymous 2014-07-05 12:25

I took my van to a Dodge dealer for an hour. The total cost was $102 — they tested the TCM and confirmed it wasn't communicating properly. I will now contact All Computer Resources, Inc., where I purchased the original TCM, to request either another replacement or a refund.

Anonymous 2014-07-05 17:34

Are you planning any wiring or circuit checks before continuing with part replacements? Blindly replacing components without diagnosing underlying issues is not recommended.

Anonymous 2014-07-05 20:51

Kev2, the dealership also inspected the wiring harness connections to the TCM. They found no communication from the TCM and could not retrieve any updates or data. Should I ask for a specific diagnostic checklist? Thanks for your help.

Anonymous 2014-07-05 21:37

I interpret that initially you had three codes: P0500, P0700, and P1698. After replacing speed sensors and installing a new TCM, only P0700 remains — is that correct? Codes P0500 and P1698 are often linked to wiring issues affecting the TCM. The TCM receives 12V power from several sources: the transmission relay (obvious), but also from pins 8, 11, and 56. These should be checked — I'll verify the exact pin numbers tomorrow when I have access to a TCM wiring diagram.

Anonymous 2014-07-25 12:32

Hi Kev2. Just returned from vacation. Thanks for the helpful tip! I’ll have my mechanic inspect the 12V power feeds and check TCM pins 8, 11, and 56.

Anonymous 2014-08-15 16:26

I’m curious about the outcome of this thread. I own a 2001 Caravan SE that’s stuck in limp mode (transmission in 2nd gear). The digital odometer showed codes: P1684, 0601, 0420, 0700, 0442, 0455, 1193. I’ve replaced the O2 sensor, MAP sensor, throttle body, and mass airflow sensor. The battery is new, and I've done routine maintenance. I haven’t addressed the catalytic converter or EVAP system yet. I was planning to trade it in until this issue arose. I read that a common ground strap might be needed — but can't find one. Any suggestions would be appreciated.

Anonymous 2014-08-15 17:11

Mav4G, consider starting a new topic with current codes and a clear description of the problem — this increases visibility and engagement on the forum.

Anonymous 2014-08-15 18:37

Kev2 — after a long call with All Computer Resources, they sent me a replacement TCM. I disconnected the battery and TCM harness for over an hour. After installing the new unit, I reconnected everything. The engine started, and the check engine light did not come back on! I’ve driven about 180 miles since — no codes appear. Thank goodness! Lesson learned: When purchasing sensitive components like a TCM, always buy from the dealership. This experience has saved me from further issues. Thanks to everyone for your support and advice!