2000 expy trouble codes

[docraymund]

Good day, my 2000 expy 4.6L is having a misfire. It is still drivable even with the a/c on but recently the misfire became worse after running for about 20 mins. If you turn off the engine and restsrt it, it runs well again. Trouble codes were:
1. B1428 GEM lamp seatbelt circuit failure
2. B1869 PCM lamp airbag warning indicator circuit open
3. B1892 PCM Airbag tone warning indicator circuit failure
4. B1318 PCM battery voltage low
5. P1000 PCM OBD system readiness not complete
6. P0171 PCM system too lean bank 1
7. B1676 ABS/TCS Battery pack voltage out of range
8. B1318 GEM battery voltage low
9. B1352 GEM Ignition key in ciruit failure

Any ideas will be much appreciated. Thank you very much!

 

[toms89]

Since you have 2 codes indicating low voltage I would check the battery volts both with vehicle on and off. Should be in the neighborhood of 12.5 volts (vehicle off) and 14.5 volts (vehicle running).

If that checks out you may have bad terminal, connection or wiring going to the battery.

Low voltage can cause a host of issues with the pcm so that would be where I would start.

 

[docraymund]

Thank you very much for the suggestion the battery and alternator might be ok because the voltmeter on the dash indicates an adequate voltage reading might well be the connections that are at fault. I just don't know where to start looking. Thanks again.

 

[Lightnig]

...

battery and alternator might be ok

...

might be???


I wouldn't trust any dash gauges to give a very accurate value.

I would strongly recommend throwing a good quality multimetre on it to get an accurate reading - or take it to the local parts store to test it for you.

Go with Toms advice and get it verified good before moving on in your troubleshooting. As he mentioned battery voltage is mentioned multiple times in that list of yours, so I strongly suspect that they are definately not ok.

 

[docraymund]

Thank you very much, come to think of it the battery is about maybe 3 years old. I recently charged it to start the truck. I will buy a new battery and hope it works. Thanks.

 

[Lightnig]

Instead of simply replacing it, I'd have it tested. Any decent autoparts store will for that for free.

No use paying for new parts without knowing if the old ones are any good or not. Well, unless you got money to burn and don't mind replacing perfectly good stuff...



Besides, I'd more suspect the alternator/regulator than the battery itself

 

[docraymund]

Thanks I will have the battery and alternator tested first sure hope it's only the battery since alternators are costly to repair or replace. Thanks again.

 

[Lightnig]

Let us know what you find, either so we can remember that for future reference or help with the next steps...