Engine - Surge at Low Speed, Rough Idle After Cold Start
Bulletin No.: T-93-9File in Group: 6E
Number: 102
Corp.Ref. No.: 216105R
Date: Oct. 1992
SUBJECT:
ENGINE SURGE AT LOW SPEED, ROUGH IDLE AFFER COLD START, OR LONG CRANK TIMES AFTER A HOT SOAK
MODELS AFFECTED:
EARLY 1993 ALLANTES
Some 1993 Allantes may experience one of the following conditions:
^ Engine surge at low speed
^ Rough idle after cold start
^ Long crank times after a hot soak
These conditions may be corrected by replacing the PCM PROM calibration. Check the PCM PROM I.D. using on-board diagnostics. If the PROM I.D. (parameter PD99) in the vehicle is lower than 2103, relace the PROM with P/N 16179000 (broadcast code AZYD).
To repair this condition use the following procedure:
1. Prior to changing PROM record transmission oil life remaining by using PCM override PS15.
2. Replace PCM PROM per published Service Information Manual procedure in Section 6E-A.
3. Turn ignition on. Diagnostic trouble code 80 (TPS/Idle Learn Not Complete) should be set.
4. Go into PCM overrides and slew transmission oil life via override PS15 to the value recorded in step 1.
5. Turn the ignition off for 20 seconds. This will force TPS learn to occur.
6. To perform idle learn, warm up the engine to 85~C coolant temperature. Then idle the vehicle in gear with the climate control in the "ECON" mode with brake and not touching the throttle for 60 seconds or until code 80 becomes a history code ("Service Engine Soon" goes out).
7. If code 80 will not become a history code, perform steps 5 and 6 again. If still not successful, check the throttle linkage for any binding conditions and for accelerator pedal interference (with floor mats, etc.) which could be causing the throttle switch to remain open or for a brake switch malfunction.
NOTE:
This PCM PROM contains a new PCM code P080, TP Sensor/Idle Learn Not complete. This code will be set any time the TP Sensor or idle learn values have not been stored in the PCM. Performing the Sensor and idle learn procedures listed in this bulletin and in the appropriate Service Information Manual will cause code P080 to become history. Clear PCM codes when the TP Sensor and idle learns are completed.
Parts are currently available from GMSPO.
For warranty purposes use Labor Operation J6364 at .6 hour.