Operation Section Table 2. Diagnostic Fault Codes (Flash Codes) cont’d. (*) Fault actions shown are default values specified by the OEM. 73 DFC PROBABLE FAULT FAULT ACTION * CORRECTIVE ACTION FIRST CHECK 491 (29) HbridgeFault ETC _ Electronic Throttle Control Driver has failed. Indeterminate fault on Hbridge driver for electronic throttle control.
Possibly either ETC+ or ETC- driver signals have been shorted to ground TurnOnMil Check ETC driver wiring for a shorted circuit SECM Pin A17 to ETC + Pin 1 SECM Pin A18 to ETC - Pin 4 • Perform the throttle test using the Service Tool and re-check for fault Check the ETC internal motor drive by disconnecting the throttle connector and measuring the motor drive resistance at the throttle TPS Pin 1 (+DRIVER) to Pin 4 (-DRIVER) ~3.0-4.0Ω 521 (52) LowOilPressureFault Low engine oil pressure (1) TurnOnMil (2) DelayedEngine Shutdown (3) CheckEngine Light Check engine oil level Check electrical connection to the oil pressure switch SECM Pin B9 to Oil Pressure Switch 531 (53) SysVoltRangeLow System voltage too low TurnOnMil Check battery voltage • Perform maintenance check on electrical connections to the battery and chassis ground • Check battery voltage during starting and with the engine running to verify charging system and alternator function • Measure battery power at SECM with a multimeter (with key on) SECM Pin A23 (DRVP) to SECM Pin A16 (DRVG) SECM Pin A23 (DRVP) to SECM Pin B17 (DRVG) 541 (54) SysVoltRangeHigh System voltage too high TurnOnMil Check battery and charging system voltage • Check battery voltage during starting and with the engine running • Check voltage regulator, alternator, and charging system • Check battery and wiring for overheating and damage • Measure battery power at SECM with a multimeter (with key on) SECM Pin A23 (DRVP) to SECM Pin A16 (DRVG) SECM Pin A23 (DRVP) to SECM Pin B17 (DRVG)