82 Crossfire Map Sensor No Ground Continuity
Thread Starter
6th Gear
Joined: Aug 2023
Posts: 6
Likes: 0
82 Crossfire Map Sensor No Ground Continuity
No ground continuity. Going out of the manual, 6E-44 Engine Emission Controls. I have back pinned the connector and have 5 volts on the 416 C terminal. Used a vacuum pump set at 20HG and am not getting any voltage on the Signal wire 432 B terminal. Then I checked 455 ground terminal A for continuity to ground on alternator. No Ground! Code 33 says check for open in CKT 469 which I can not find on wiring diagram. Check for short to voltage 432. If CKT 432 OK Replace ECM. The car is running so rich and rough that I cannot confirm ( Closed Loop ) operation and I dont know if that makes a difference with signal and ground from ECM. With the key on and not using the paperclip jumper on diagnostic, I have checked the TPS, set and confirmed voltage output with this backpin method at the harness. I hope its not the ECM because good luck finding one. Any help greatly appreciated.
Safety Car
Joined: Nov 2005
Posts: 3,532
Likes: 1,185
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
Just to give you a heads up on the wiring diagram. There is NO CKT 469, it's a misprint by GM. It is CKT 455 that you want to look at. Make the note in your book. So, if your ECM is in fact bad, not to worry, I have your solution...PM if that is true. 
Thread Starter
6th Gear
Joined: Aug 2023
Posts: 6
Likes: 0
I was just checking for continuity with multimeter for the CKT 455 Ground on MAP sensor with it back pinned. If the ECM is grounded for CKT 455, would it not show grounded using the body ground or alternator ground with multimeter to back pinned ( paper clip ) ground wire on MAP sensor plugged in?
Safety Car
Joined: Nov 2005
Posts: 3,532
Likes: 1,185
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
Melting Slicks
Joined: May 2021
Posts: 2,274
Likes: 1,317
From: Fleming Island, FL
I was just checking for continuity with multimeter for the CKT 455 Ground on MAP sensor with it back pinned. If the ECM is grounded for CKT 455, would it not show grounded using the body ground or alternator ground with multimeter to back pinned ( paper clip ) ground wire on MAP sensor plugged in?
Last edited by Fly skids up!; Sep 6, 2023 at 03:48 PM.
Drifting
Joined: May 2020
Posts: 1,663
Likes: 702
From: Baton Rouge, Louisiana, metro area
If you haven’t already, confirm good fire to all your plugs. Had one where one plug wire was dislodged from the distributor under the shield. Likely not that simple, but I always check the easy/cheap first.
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