Well, I noticed the other day when starting my 2003 blazer LS that the SES light wasn't lit up. I decided to take it to see if it had any codes or not. When they hooked it up, it came up with 20 codes. Thankfully some were duplicates but after wiping those out, I was still left with 14. Any suggestions on what to hit first and how to touble shoot them to fix it would be appreciated. The codes are as followed:

B0036
U1000
U1096
U1064
C0226
C0223
C0222
C0221
P0101
P0128
P0335
P0446
P0452
P0463

 

your truck thinks it's totaled.

 

Here's the description on all of the codes:

• B0036 - Auxiliary Discriminating Sensor (ADS) Open, Missing, or Shorted to Battery
• U1000 - Class 2 Communication Malfunction
• U1096 - Class 2 Data Link Communication Error - Instrument Cluster
• U1064 - Class 2 Data Link Communication Error - BCM
• C0226 - Missing Front Left Wheel Speed Sensor Signal
• C0223 - Erratic Front Right Wheel Speed Sensor Signal
• C0222 - Missing Front Right Wheel Speed Sensor Signal
• C0221 - Right Front Wheel Speed Sensor circuit open
• P0101 - Mass Air Flow System Performance
• P0128 - Engine coolant fails to reach preset target temperature
• P0335 - Crankshaft Position Sensor 'A' Circuit Malfunction
• P0446 - Evaporative Emission Control System Vent Control Circuit
• P0452 - Evaporative Emission Control System Pressure Sensor Low Input
• P0463 - Fuel Level Sensor Circuit High Voltage

 

If the ignition switch was having issues, would I have issues starting the vehicle? It starts every time without issue so far. Only time it didn't was when the started went out.

 

The thread I mentioned above shows the inside of the switch along with wiring diagrams and connector pinouts. As you will see, there are a total of 5 different circuit contacts inside the switch. Only one contact is responsible for energizing the starter relay and since the starter circuit has a relay, there really isn't much load on the contact.

The IGN1 & IGN3 circuits have much more current flowing through the contacts in the ignition switch and are the ones that typically will burn out. The IGN1 circuit specifically powers the SIR and GAUGES fuses among others. The IGN3 circuit powers the ABS system among others.

Testing the contacts requires a multimeter and can be done by testing the resistance or voltage drop from the input to the output sides of the contacts. You would want to disconnect the ignition switch connector for the resistance test while the voltage drop test is done with everything connected and powered up. For IGN1, you'll test the large red wire (B1) to the large pink wire (C5). For IGN3, large red wire with white stripe (D2) to the large orange wire (C6). The contacts for IGN1 are closed in RUN & START while the contacts for IGN3 are closed in RUN only.