F 250 2WD Pickup V8-7.3L DSL (1990)
Technical Service Bulletin # 9012B13
Date: 900611
HEGO Sensor - Diagnosis, Manual Revision
ENGINE/EMISSIONS DIAGNOSIS SHOP MANUAL - 1990 - 7.5L ENGINE HEGO SENSOR REVISED FROM 3-WIRE TO 4-WIRE - PINPOINT
TEST SCHEMATICS UPDATED
Article No. 90-12B-13
LIGHT TRUCK:
1990 BRONCO, ECONOLINE, F-150, F-250, F-350
ISSUE:
The 3-wire HEGO sensor has been replaced with a 4-wire sensor on 1990 7.5L EFI truck. The 1990 4.9L EFI truck 4-wire sensor is not
grounded to SIG RTN in the harness as shown in the 1990 Engine/Emissions Diagnoisis Shop Manual.
ACTION:
Refer to the pages following this TSB article for the updated schematics and pinpoint test procedures.
OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: INFORMATION ONLY
OASIS CODES:
2800
