Canada - Engine Controls - ECM Non-Interchangability

GROUP
ENGINE ELECTRICAL

NO.
01-36-010

DATE
AUGUST 31/01

MODEL
V6 SANTA FE
V6 SONATA EF

SUBJECT

ECM NON-INTERCHANGEABILITY FOR
2001 V6 SANTA FE AND
1999~2001 V6 SONATA

When diagnosing certain engine performance related problems where you feel the ECM may be at fault, special attention MUST be made when swapping ECMs from known good vehicles to and from 1999~2001 V6 Sonata EF's and 2001 Santa Fe's.

Before ordering and replacing an ECM for the vehicle you are servicing, swapping an ECM from a known good vehicle is a good diagnostic tool. But, when doing so, the ECM MUST come from a vehicle with identical vehicle specifications as the vehicle you are servicing (i.e. if the servicing vehicle has ABS, you MUST only use an ECM from an ABS equipped vehicle, and vice versa).

Since all V6 equipped Hyundai vehicles have Automatic Transaxles, you must match the vehicle with ABS, or no ABS, in addition to matching the model year. (ECM part numbers from May, 2000 do not specify if the vehicle has ABS or no ABS.)

If an ECM is swapped between non-matching vehicles, the Malfunction Indicator Lamp (MIL) and a Diagnostic Trouble Code (DTC) could be falsely set, thereby making your diagnosis much more difficult.

Note:
Having identical ECM part number is NOT sufficient.
^ The ECM part number is the same with or without ABS.
^ The ECM part number is the same with or without an ATM.

The reason for this is: a new "unlearned" ECM learns, and remembers, its particular parent vehicle's details. Once the information has been "learned", the ECM expects the required information and processes the required information accordingly. The "learned" information CANNOT be unlearned, even if power to the ECM is disconnected.

For example:
The vehicle you are servicing is a 2001 Santa Fe (V6 with ATM) and has ABS. Temporarily installing an ECM from a Santa Fe (without ABS) you may have in inventory will set a P0500 (Vehicle Speed Sensor Malfunction) after or during a test drive.