1991 Pontiac Bonneville CAM sensor code 41

Tiny
ASTRO 50
  • MEMBER
  • 1991 PONTIAC BONNEVILLE
Engine Performance problem
1991 Pontiac Bonneville 6 cyl Front Wheel Drive Automatic

have a boniville that sents code 41 already replaced cam magnet new cam sensor new crank sensor tried 3 diffrent ignition modules has signal out of crank sensor can generate signal into ecm when bypassing the ignition module and no code sets checked all wiring replaced pig tail to cam sensor when running or key on the signal wire has 12 volts on it cut wire to pcm and pcm side doesn't have voltage onit
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Thursday, May 7th, 2009 AT 2:07 PM

8 Replies

Tiny
MERLIN2021
  • EXPERT
Engine crank or not?
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Thursday, May 7th, 2009 AT 3:12 PM
Tiny
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Engine runs fine no other problems code is class b sets on second start clear code and resets on second start
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Thursday, May 7th, 2009 AT 4:28 PM
Tiny
MERLIN2021
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Did you check your email yet?
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Thursday, May 7th, 2009 AT 4:45 PM
Tiny
ASTRO 50
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Mike yes it has a 3800 engine
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Thursday, May 7th, 2009 AT 11:26 PM
Tiny
MERLIN2021
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Scroll down to code 41 in the PDF I sent you, it explains how to check the circuit as well as the sensor.
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Friday, May 8th, 2009 AT 2:55 AM
Tiny
ASTRO 50
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Merlin I don't see a link to a pdf
if it is the same as mitchell or gm code 41 flow chart it doesn't fix it any way
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Saturday, May 9th, 2009 AT 3:00 PM
Tiny
MERLIN2021
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No link, I emailed you instructions, have you checked your email? It's in depth for checking the harness and outputs at the sensor.
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Sunday, May 10th, 2009 AT 7:45 AM
Tiny
MERLIN2021
  • EXPERT


http://www.2carpros.com/forum/automotive_pictures/62217_bonnavillle41a_1.jpg



http://www.2carpros.com/forum/automotive_pictures/62217_bonnavillle41b_1.jpg



http://www.2carpros.com/forum/automotive_pictures/62217_bonnavillle41c_1.jpg



http://www.2carpros.com/forum/automotive_pictures/62217_bonnavillle41d_1.jpg


CODE 41, CAM SENSOR CIRCUIT Quick reference: See Fig. 45 for Code 41 flow chart. " See Fig. 44 for Code 41 supplemental wiring. " All Updated Information All the Code 41 information here (including the flow chart) has been updated as per the General Motors Technical Service Bulletins (TSBs) listed below. All outdated information has been discarded. Buick 91-6E-14 " Oldsmobile 91-T-45 " Pontiac 91-6-18 " Circuit Description The 3800 engine uses the simultaneous mode of fuel injection during start-up. As the engine speed attains the 400 RPM level and a cam signal has been received by the ECM from C3I module, the fuel injection switches modes to sequential injection. This is accomplished by use of a cam interrupter magnet and a cam sensor "Hall Effect" switch. The cam sensor sends a signal (sync-pulse) to the ignition module when cylinder #1 is 25 after top dead center on the compression stroke. This signal is used to start sequential fuel injection with the proper cylinder. If cam signal is lost to the ECM, the fuel delivery will switch back to the simultaneous mode of injection. THE ENGINE WILL CONTINUE TO RUN. IT WILL RESTART AFTER SHUT DOWN. Code 41 is set when the following conditions are met: Engine is running. " Cam sensor signal not received by the ECM in last 2 seconds. " Test Description The numbers below refer to the circled numbers in the diagnostic flow chart. This step verifies proper operation of circuits 633, 644, and 645. See Fig. 44 for circuit identification. 1. Step validates the integrity of Circuit 630 from the ignition module to the ECM. See Fig. 45 for circuit identification. 2. If the camshaft gear magnet is interfacing with the cam sensor the voltage reading will be zero, bumping engine will cause the condition to go away. 3. If the voltage reading of terminal "BC5" is constantly varying and connection to terminal "BC5" are good, the ECM is faulty. 4. V The magnet or gear may be damaged, Posted By: PCS agent 6 Flag Post For Monitor Review
Shop: MITCHELL 1
Date: 4/16/2009 11:00:24 AM

The Cam Gear magnet is installed from the back side of gear. The stronger side of magnet is facing towards the waterpump.


http://www.2carpros.com/forum/automotive_pictures/62217_bonnavillle41e_1.jpg

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Sunday, May 10th, 2009 AT 8:14 AM

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