Code 56 - ZR-1 Net Registry Forums

mmkkpro · 10-20-2019

Hi guys, hope everyone is well. I'm working on my last code a 56, vacuum sensor circuit. The FSM says if the ECM is reading a low or high condition the ECM and wiring is OK. Have any of you guys had this code and if so what corrected it?
Now, when I switch the ignition on my little vacuum pump runs for about 10 seconds and shuts off but comes back on fairly quickly, which tells me I have a leak. When I had the plenum off I checked all hoses and secondary parts, tested it and it held vacuum. With the engine idling the pump does not run. Yall think the small vacuum leak would cause the code 56? I have 18 inches of vacuum at idle hot. I have been looking for another sensor but no luck yet. Thanks

10-20-2019	#1
mmkkpro Join Date: Apr 2019 Location: Supply NC Posts: 124	Code 56 Hi guys, hope everyone is well. I'm working on my last code a 56, vacuum sensor circuit. The FSM says if the ECM is reading a low or high condition the ECM and wiring is OK. Have any of you guys had this code and if so what corrected it? Now, when I switch the ignition on my little vacuum pump runs for about 10 seconds and shuts off but comes back on fairly quickly, which tells me I have a leak. When I had the plenum off I checked all hoses and secondary parts, tested it and it held vacuum. With the engine idling the pump does not run. Yall think the small vacuum leak would cause the code 56? I have 18 inches of vacuum at idle hot. I have been looking for another sensor but no luck yet. Thanks