Does not start after replacing mass airflow sensor and MAP sensor

JDAVIS673

MEMBER
2010 CHEVROLET TAHOE
5.3L
V8
2WD
AUTOMATIC
166,000 MILES

After I got the reduced power to engine warning the engine shut off then was rear ended. Once towed I was able to put a scan tool on and it gave codes for the mass airflow sensor and MAP sensor being bad. I replaced those and the throttle position sensor. Now the engine will not start. Unsure of what to do next.

Monday, December 6th, 2021 AT 12:08 AM

3 Replies

JACOBANDNICKOLAS

MECHANIC
110,101 POSTS

Hi,

If you disconnect the MAF, will it start? By disconnecting it, it should put it into a preset mode which allows the engine to continue running. Also, what codes did you find when it was originally checked?

I want to try a test. Will it start for a couple of seconds if you use starting fluid?

Let me know.

Joe

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Monday, December 6th, 2021 AT 6:41 PM

JDAVIS673

MEMBER
3 POSTS

I removed the MAP, and it didn’t start. I’m thinking it might be a switch on the fuel pump or something like that that gets tripped when in a collision. Not sure though.

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Monday, December 6th, 2021 AT 8:39 PM

JACOBANDNICKOLAS

MECHANIC
110,101 POSTS

I looked through the wiring schematic for the starting system and don't see a traditional automatic shutdown relay.

How hard were you hit from the rear? Also, have you checked to see if the engine is getting spark and fuel? Will it start with starting fluid and then shot down?

Let me know.

Joe

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Tuesday, December 7th, 2021 AT 7:48 PM