Hi guys. I replaced the #4 injector about a month ago and its giving code P0272 again. I also get codes for #'s 5,7 and 8. I clear the codes and #5 and #7 are constant but "4 and #8 don't always come up is there any ideas or ways to figure put what is wrong. I only have a code reader I can't do any testing or buzz tests. Please help.

 

I would say you have a bad #4 injector or bad cylinder. Please post all the codes you are getting for each cylinder. Also, check your FICM voltage while the truck is COLD.

 

P0272, P0275, P0281, P0284, P0403, P0405, P0528, P0620, & P1000

 

You definitely have some wiring issues to start with:

OBD Code P0620 refers to
The PCM uses the generator turn on signal circuit to control the generator. A high side driver within the PCM allows the PCM to turn the generator ON and OFF. When Generator operation is desired, the PCM sends a 5 volt signal to the voltage regulator via the generator turn on signal circuit. This causes the voltage regulator to begin controlling the generator field circuit. Once the Generator is enabled by the PCM, the voltage regulator controls generator output independently of the PCM. Under certain operating conditions, the PCM can turn Off the generator by turning Off the 5 volt signal on the generator turn on signal circuit.
Symptoms
Possible sumptoms of OBD code P0620
- Engine Light ON (or Service Engine Soon Warning Light)
Causes
Possible causes of OBD code P0620
- Failed Generator/Belt - Battery charge - PCM controlled generator - PCM failure - Open or short generator circuit The Error code is generally activated on detection of the following conditions: The PCM has fault detection circuitry which monitors the state of the generator turn on signal circuit. If the fault detection circuit senses a voltage other than what is expected, this DTC will set. The voltage regulator also contains fault detection circuitry. If the regulator detects a problem, the regulator will ground the generator turn on signal circuit, pulling the voltage low. This also causes the PCM to set the DTC.

P0528, P0403, P0405--check the wiring to and around your fan clutch to see if they are cut/broken.

The contribution balance codes--Check the FICM voltage first, load test the batteries individually and have the alternator tested. Usually C/B codes indicate bad injectors but you may have other things going on.

 

So its possible that one of my alternators are bad and could be contributing to my problem. My charging system never gets above 13.4 volts when driving.