DeVille V8-252 4.1L VIN 8 FI (1983)
Throttle Position Sensor: Customer Interest
A/T - High Idle/Intermittent Code 26, Improper TPS
Bulletin No. T
85-7
File In Group
6C
Number
85
Date
Sept. '84
SUBJECT:
HIGH IDLE AND/OR INTERMITTENT CODE 26
MODELS AFFECTED: ALL 1981-1985 MODELS EQUIPPED WITH DFI
THROTTLE POSITION SENSOR TYPES
Some 1981-1985 DFI equipped vehicles may experience a high idle and/or an intermittent code 26, under various operating conditions due to the
installation of an improper Throttle Position Sensor (TPS) while servicing the vehicle.
The 1981 V8-6-4 TPS, although similar in appearance, is different electrically than the ones used for 1982-1984 HT4100 equipped vehicles. The ECM
will not interpret the throttle angle correctly if these parts are interchanged. A 1981 V8-6-4 TPS installed on an HT4100 equipped vehicle can be
diagnosed by a higher than normal throttle angle at warm idle (i.e., 4-6 degrees on parameter .0.1 vs. approximately 0-2 degrees on a normal vehicle)
when the TPS is properly adjusted. The 1984 TPS is different in appearance than the 1981-1983 TPS.
As with all electrical and emissions-related parts, it is essential that the correct service part be used. Part numbers areas follows:
Model Year
Engine
Service P/N
TPS "I.D."
Application
Type 1
1981-1984
368 CID (V8-6-4)
17067979
59085
"D" Limousine and 1981
C,E,K
Type 2
1982-1983
HT4100
17078259
70898
C/E/K
Type 3
1984-1985
HT4100
17110352
74958
DW/DM/E/K (Excluding
Limousine)
TPS "I.D." LOCATIONS