Lights - Headlight Dimming On Deceleration
NO. TSB-94-54-003DATE: November, 1994
MODEL: See list below
SUBJECT:
HEADLIGHT DIMMING ON DECELERATION
BACKGROUND INFORMATION
Some customers may notice a momentary headlight dimming during deceleration on 1994 or 1995 Galants (vehicles built up to 4/28/94). The dimming may also be seen in the dashboard lights. This condition may be caused by the engine's Electronic Control Module (ECM).
During deceleration, the ECM sends a signal to switch on The cooling fan, creating a battery draw and a momentary dimming of the lights. Vehicles equipped with an automatic transmission are more likely to experience this condition than vehicles with a manual transmission. To correct the condition, install an ECM Modulator Kit as described in this bulletin.
VEHICLES AFFECTED
1994 Galant
1995 Galant. up to build date 04/28/94, up to VIN 4A3AJ56GXSE006135
DESCRIPTION
If a customer complains of headlight dimming during vehicle deceleration, install an ECM modulator kit (part number MD32O48O).
The ECM Modulator Kit consists of three parts:
Installation Procedure for ECM Modulator Kit, P/N MD320480
1. Record the radio presets and disconnect the negative battery terminal.
2. Remove the passenger-side lower console cover to gain access to the ECM. The ECM is elevated, located behind the audio unit. On A/T equipped vehicles, The ECM is positioned above the Transaxle Control Module (TCM).
Detach the metal bracket on The right side of the ECM and disconnect the ECM wiring harness connectors.
3. Attach the 3 yellow modulator harness connectors marked "ADP" to either side of The adaptor plug.
4. Attach the sub-harness to the clear 9-pin connector of the modulator harness then connect the sub-harness to the modulator.
NOTE:
See parts information.
5. Attach the 3 gray modulator harness connectors marked "ECU" to the ECM.
6. Attach the 3 original ECM wiring harness connectors to the open end of adaptor plug.
7. Remove the adhesive strip covers from the adaptor plug and modulator. Place the adaptor plug and modulator under the ECM, using the adhesive strip to secure the components to prevent movement
8. Attach the metal bracket on the right side of the ECM.
9. Install the side console cover.
10. Attach the negative battery terminal, set the clock, and reset the radio presets.
11. Verify the condition no longer exists. If the wiring harness is installed improperly, the A/C compressor clutch will cycle at 1-2 second intervals, the condenser fan will run continuously, and the vehicle will have poor driveability. Should this condition be encountered after performing the procedure in this bulletin, repeat steps 1 through 11.
PARTS INFORMATION
The ECM Modulator Kit, part number MD32O48O, is available from your facing PDC.
Modulator kits in the future will not require a sub-harness. For kits that do not include the sub-harness, please skip step # 4.
WARRANTY INFORMATION
Labor Operation Code: 54899910
Position Code: 548999
Nature Code: 59H
Causal Code: 470
Time Allowance: 0.5 hours.