Shadow Convertible L4-153 2.5L SOHC (1994)
Speedometer Module: Technical Service Bulletins
Speedometer - Inaccurate or Erratic Diagnosis
NO: 08-39-94
GROUP: Electrical
DATE: Aug. 5, 1994
SUBJECT:
Speedometer Erratic Or Inoperative Diagnosis
MODELS:
1994 - 1995
(AA)
Spirit/Acclaim/LeBaron Sedan
1994
(AP)
Shadow/Sundance
DISCUSSION:
When diagnosing an erratic or inoperative speedometer on the subject vehicles an additional test beyond those listed in the service manual may be
required. These vehicles are equipped with a passenger side motorized seat belt system. The Passive Belt Control Module (PBCM) is the electronic
controller for this system.
The vehicle speed sensor signal is provided to the PBCM and is used to prevent the motorized seat belt's movement from the "B" post position if the
door is opened while the vehicle is in motion.
An internal short within the PBCM (which is connected to the speedometer - vehicle speed sensor wiring circuit) can result in an erratic or inoperative
speedometer. To determine if the PBCM is the source of the speedometer complaint, disconnect the PBCM. If the speedometer operates correctly with
the PBCM disconnected, replace the PBCM.
POLICY: Information Only
