Safari Van M V6-262 4.3L VIN Z TBI (1990)
Wheel Speed Sensor: Customer Interest
ABS - Wheel Speed Sensor False Code 65
GMC NUMBER:
91-5E-12
GROUP:
5E ANTI-LOCK BRAKES
DATE:
AUGUST, 1990
CORPORATE
NUMBER:
065015
SUBJECT:
FALSE CODE 65 SET WITH WHEEL SPEED SENSOR CODES 23, 27, 28, 29, 33, 37
MODELS:
1990 M/L VANS AND 1991 S/T 4 DOOR UTILITY VEHICLES WITH 4 WHEEL ANTI-LOCK BRAKES
In the event a problem is experienced with the input of speed signal from the wheel speed sensors any of the following codes may be set:
The root cause of these codes could be a malfunctioning sensor or shorted sensor wires or a loose or damaged 8 pin connector.
A peculiarity within the 4WAL system may set a code 65 at the same time codes 23, 27, 28, 29, 33, and 37 are set. Code 65 usually indicates that the
pump motor relay has an open circuit which would require the replacement of the EHCU (Electro-Hydraulic Control Unit). When set with the above
sensor codes, however, this is a FALSE code and the EHCU SHOULD NOT BE REPLACED. Once the appropriate sensor repair has been made the
codes should be cleared and a function test of the system, using Tech 1 should be made.
A software revision has been made in production to eliminate the false code 65 setting with codes 23, 27, 28, 29, 33, and 37 on vehicles built after the
following VIN breakpoints:
M Van
GMC
LB543964
CHEVROLET
LB225290
L Van
GMC
LB544127
CHEVROLET
LB225573
