Let me start by saying i have a H/C 99 Fixed roof coup. When i recieved the car the tune was not the best, but progressively got worse as summer started. Breaking up everytime i drove the car, i assumed it was just cam buck but as it got worse it was apparent that was not the cause. It would get better in the higher rpm ranges... needless to say, I needed a tune badly.

I took it to get the OBDII codes read and i had a sensor 2 bank 1 running lean msg.

Fastfoward to this past week i took the car to an extremely well known shop here in NC. When they got the car it would not hold a steady idol, going from 400 - 1200 rpm randomly.

The o2 sensor wires were laying on the header and the wires burned through, causing the o2 sensors to stop working. This caused alot of carbon build up on the o2 sensors and plugs.

After replacing the plugs, the o2 sensor fuse was blown. After replacing that the shop started tuning. The whole way home the car ran perfect, getting over 30mpg, smooth idol, almost perfect. No warning lights on. The next time i drove the car was today.

When i started the car i recognized a code on the OBC, it read CHARGE SYSTEM FAULT. The CHECK ENGINE light was also on, I needed to get to class so I ignored both codes and was planning on looking into it after class.

After class i took it to Autozone to get the OBDII codes read for a second time. The code was P0155. also listed under the definition is : H02S21- heater condition (heated oxygen sensor bank 2 sensor 1). Listed is the powertrain control module monitors the oxygen sensor heater. the computer has recognised a failure in this circuit. Probable causes were listed as oxygen sensor defective, poor connection at oxygen sensor, and check circuit fuse. Later, I checked the fuse but it was still good.

As i was on my way home the CHECK GAUGES light appeared, accompanied by these readings on the OBC: LOW VOLTAGE, SERVICE ABS, and SERVICE TRACTION CONTROL. The voltage reading was below 11 when i cut the car off in the garage.


here is a list of the OBC Readings:
Charge System Fault
Service ABS
Service Traction System
Low Voltage
Check Guages
Check Engine
Bank 2 Sensor 1 - H02S21

this is a list of the codes the car was throwing:

10 PCM - 3 Codes
-P0155 H C
-P1637 H
-P1698 H C

28 TCS - 4 Codes
-C 1221 H
-C 1222 H
-C 1236 H
-U 1016 H

40 BCM - No Codes

58 SDM - 3 Codes
-U 1000 H
-U 1016 H
-U 1064 H

60 ICP - 7 Codes
-U 1016 H
-U 1064 H
-U 1040 H
-U 1088 H
-U 1176 H
-U 1005 H
-U 1160 H

Any help would be greatly appreciated as i am still in college and have already spend

over $1000 trying to fix these problems.

 

Sounds like the Voltage regulator is on it's way out or your battery is too.

 

This might give you some places to start...

http://www.stengel.net/diccodes.htm

Codes ending with "H" are history and ending with "C" are current.

 

Can you borrow a battery from a friend and start it with a known good battery? Once it starts, check the voltage across the terminals to see if it is charging. When these batteries start getting bad, crazy things start to happen so don't panic and take a systematic approach to figuring it out.

 

so the code P1638 Generator F-Terminal Circuit means the alternator is probably the cause?

the other code P0155, is related to the bank 2 sensor 1 o2 sensor. if it is not the fuse, and the o2 sensor just got replaced for the tune... what would a safe assumption for this problem be?

i do have class tomorow but i have no way to get there. please help.

 

If you have an Autozone around, the alternator comes out in 5 minutes. Pull it out and have them bench check it. You need a 15mm socket and a 13 mm wrench if I remember correctly and 8mm to remove the battery terminal before removing the alternator.

Disconnect battery
Unplug alternator
Remove main wire from alternator
Loosen belt and slide off
Remove alternator