Wednesday, February 23, 2011

cadillac cts 2003 error codes explanation?

P0036 Error Code On Cadillac

P0036 - Heated Oxygen Sensor (HO2S) Heater Control Circuit Bank 1 Sensor 2.

Ho2s on Cadillac

Cadillac Oxygen Sensor Connector Details

At the connector are you getting voltage? Pin D? Check this.

How To Replace Oxygen Sensor:



  • Remove oxygen sensors (O2S) with the engine temperature above 48°C (120°F) . Otherwise the O2S may be difficult to remove.
  • A special anti-seize compound is used on the O2S threads. New service sensors should already have the compound applied to the threads. Coat the threads of a reused sensor with anti-seize compound P/N(NNN) NNN-NNNNor equivalent.

  1. Raise and support the vehicle.
  2. Remove the heat shield.
  3. Disconnect the heated oxygen sensor (HO2S) electrical connector.
  4. Remove the HO2S.


  1. Install the HO2S. NOTE: Refer to Fastener Notice in Service Precautions. Tighten the HO2S to 41 N.m (30 lb ft) .
  2. Connect the HO2S electrical connector. IMPORTANT: Ensure connectors are securely installed beneath harness heat shield to prevent connector damage.
  3. Install the heat shield.
  4. Lower the vehicle and perform a code clear.

Yes bank 1 sensor 2: Sensor after the catalytic converter, there is only 1 catalytic converter

Well either you have a bad pcm or the wiring between the o2 sensor is broken somewhere. I would advise leaving this one to the experts at a shop. This isn't a typical repair.

P0300 Random Misfires can be tricky but normally caused by vacuum leak and contaminated fuel-

Engine running rough or misfiring can be cause by the following:

1.Defective spark plugs
2.Inadequate spark/coil, defective spark plug wire.
3. Lack of compression
4.False air leakage.
5. Faulty fuel injectors.
6. Insufficient fuel pressure.
7. Contaminated fuel.
8. EGR valve that is leaking.
9. Oxygen sensors.
10. Throttle position sensor.
11. Manifold absolute pressure sensor
12.Mass Airflow Sensor
13.Idle air control valve.

The number in p0300 code indicates which cylinder is causing the problem.If the last number is p0301 then cylinder number 1 is misfiring.If the number is p0302 then cylinder 2 is misfiring and causing the problem.