Pontiac Fiero 1988 Service Manual page 509

6E2-A-54 DRIVEABILITY AND EMISSIONS - FUEL INJECTION (TBI)
CODE 51
CODE 53
2.5L " P " SERIES (TBI)
C O D E 51
FAULTY PROM
CHICK THAT ALL PINS ARE FULLY INSERTED IN THE SOCKET A N D THAT PROM IS PROPERLY SEATED.
IF OK, REPLACE, PROM, CLEAR MEMORY, A N D RECHECK. IF CODE 51 REAPPEARS, REPLACE ECM.
CLEAR CODES AND CONFIRM " C L O S E D L O O P " OPERATION AND NO "SERVICE ENGINE S O O N " LIGHT.
C O D E 53
SYSTEM OVERVOLTAGE
THIS CODE INDICATES THERE IS A BASIC GENERATOR PROBLEM .
• CODE 53 WILL SET, IF VOLTAGE AT ECM TERMINAL B2 IS GREATER THAN 17.1
VOLTS FOR 10 S E C O N D S .
• CHECK AND REPAIR CHARGING S Y S T E M . SEE SECTION 6 D .
CLEAR CODES AND CONFIRM " C L O S E D L O O P " OPERATION AND NO "SERVICE ENGINE S O O N " LIGHT. 11-7-86
* 7 S 3 3 3 1 - 6 E