Codes, 13, 29, 78

[Don H]

Truck died yesterday but started back up again. went to mechanic to pull codes and this is what he told me.
13 Pump is bad
29 Vacuum pump bad
by correcting these two would get rid of 78
I will be replacing fsd today but will it clear 78 and is it a common problem for vacuum pumps to go bad, replaced at 186,000 now 257,000
thank you for your help

[moondoggie]

Good Day!

Do a search on 78, or vacuum, or

[ttpost]

uhmm, are you sure of the code #s, i double checked my chart and code 13 is engine shutoff solenoid, 29 is glow plug relay and 78 is wastgate, although my codes are for a 94 computer obd1, i think your 95 is the same (?). you might want to check the connector at the computer and the one in the back of the block. i know the glow plug relay and the shutoff run off of the same pink/black wire not sure about the wastegate. or possibly the ingition switch.this is what i found in my limited experience with this truck. hope this helps. smile.gif

[gmctd]

DTC's for OBD-I and OBD-II are listed in Member's Area, Topics section.

As is some troubleshooting procedures for popular failures.