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P1646 Diagnostic Trouble Code Discussion for July 2009

Hydraulic Cooling Fan Control Circuit Low

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Trouble Ticket Help Requests for DTC P1646
Help Request Posted
2000 Jaguar Vanden Plas 4.0L MIL Lamp on VIN: SAJDA24C6Y
P1646: HO2 heater circuit fault. Pulled code p1646 heater circuit fault bank A upstream sensor. replaced all 4 sensors (with Denso after market sensors) and code returned on first test drive. have checked wiring for heater relays to sensors and wiring between ecm and sensors all test and look...
July 16, 2009
1998 Buick Riviera 3.8L No Start VIN: 1G4GD2213W
P1646: Supercharger Boost Solenoid Control Circuit Malfunction. ... this on a GM 3800.We have always been able to troubleshoot and repair this engine. Anyway i could use some help on this one. The car was towed here from a shop down the road.The 3800 code one supercharged engine has good spark and good fuel pressure.The sh...
July 25, 2009