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Old 02-25-2016, 10:07 AM   #10 (permalink)
HeavyChevy95
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Actually.. On OBD2 models, the Lift Pump is monitored, at least its voltage (amp) is..

Intermittent P0231 code


P0230- Fuel Pump Relay Control Circuit
P0231- Fuel Pump Secondary Circuit Low
P0232- Fuel Pump Secondary Circuit High

More info on
P0230
P0231
P0232


As I understand it.. The PCM notes the LP voltage (amperage draw) during Startup Mode, and uses that reading to monitor the LP performance for the duration of that ignition cycle.. Thats why alot of LP failures dont SET DTCS, during STARTUP MODE, its noting the skewed voltage reading of an already struggling and/or damaged liftpump..





The IP is the last of a long list of possible suspects.. Dont be so quick to convict without all the FACTS. Rush to judgement often compounds the pain and suffering of a costly misdiagnosis..


Good Luck..

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