A/C - ECM Damage from Leaking Evaporator Drain Hose
Models: See belowSection: Heater/Air Conditioning
Classification: HA94-007
Bulletin No.: NTB94-107
Date: November 30, 1994
ALTIMA ECM DAMAGE FROM A/C DRAIN HOSE LEAKAGE
Applied Models: All Altima
SERVICE INFORMATION
When installing an A/C kit on an Altima, be careful to correctly install the evaporator drain. If the water doesn't drain properly from the evaporator case, it may leak into the vehicle interior and damage electrical components such as the ECM (located on the tunnel behind the ashtray).
A water-damaged ECM may cause driveability complaints such as rough idle, poor engine performance, and excessive smoke. To eliminate this incident, follow the instructions below for proper drain installation.
Evaporator Drain Installation (New A/C Kit)
The evaporator drain system consists of two parts - the drain nipple and the drain hose. The drain nipple is a part of the evaporator, and the drain hose is factory-installed on the engine compartment wall.
1. Remove the air duct (the air duct is replaced by the evaporator) and inspect the drain hose on the engine compartment wall. Make sure the hose grommet is properly seated on the engine compartment wall and that the hose is not deformed, kinked, or obstructed (see illustration).
2. Insert the evaporator drain nipple into the drain hose. Make sure the foam donut seal does not get caught in the drain nipple opening. Also make sure the carpet doesn't break the seal between the foam donut and drain hose. (The donut must be behind the carpet and insulator, against the bulkhead - see illustration.)
Vehicles with water damage:
1. Inspect the foam donut seal between the evaporator case and the engine compartment wall to make sure it is not obstructing the opening of the drain nipple or hose. Also ensure that the carpet isn't caught between the seal and the evaporator or fire wall.
2. Raise the vehicle and inspect the drain hose opening - remove/correct any obstruction.