good nite everyone. can someone kindly help me diagnose a few dtc codes pls. i had just pulled into my garage from a day of driving, about 15 minutes later i decided to go out again. this time when i attempted to start the car it only gave a click click sound. i checked the battery and the terminals and they were fine. next i hooked up my obd2 reader and it gave me the following codes. p0138 p1646 p1603. the p1603 code concerned me most as it deals with the tcm eeprom failure. but can some explain how these codes are related to the car not starting? It just gives a loud click click sound and the interior lights blicks on each attempt to start the car. thanks much

 

the 0138 and 1646 codes both relate to an open circuit in the right-hand bank O2 sensor and neither relate to the TCM code. None of which would seem to prevent the car from "starting". That's why I'm betting you may have a poor battery. Our cars are known to throw strange unrelated codes when the battery is weak.

 

satwarez, from what you are describing, you are falling into 1 of two conditions. The less likely of the two is you have 2 different failures that have occurred at the same time. Unfortunately, you have to deal with each issue individually and then get them fixed in such a way that you can confirm a bad part before just tossing parts at the car. This is where a good shop is going to be worth their weight in gold.

Now for the good news. Odds are, what you are experiencing is a problem with a battery cable leading to a low voltage condition inside of the car. The quick check to confirm this is to get a multimeter and connect it between the chassis of the car (black lead) and the large (battery) post of the starter (red lead, multimeter set to VDC). Now, while attempting to start the car, what does the multimeter read? If you are seeing 12.0 VDC or higher, you have a starter issue, replace the starter and see what you have at that point. If you are getting under 11.0 VDC, then you have a wiring issue with the main cables coming off of the battery or a bad battery. Repeat this test with the multimeter leads touching only the led posts of battery (not touching the wire terminals on the battery). if the battery voltage is up above 11.0, then the battery is good, problem is wiring. If the battery voltage drops below 11.0, bad battery. Please keep in mind that this assumes you have a fully charged battery to start with (can be confirmed with measuring the battery voltage with all doors shut, key out of the car, and measuring across the battery, a fully charged battery will read 12.6 VDC, anything less and you have another issue, let me know).

Our cars are very sensitive to the battery voltage at start up. You manage to get the battery voltage too low as the motor is cranking and very strange things happen. Unfortunately, it doesn't do the same thing every time.

 

Thanks guys i will conduct the checks with the multimeter and let you guys know. But first i will just try a new battery. will update you tomorrow.

 

Hi, I have a problem with my 2002 jag x-type 2.5, my battery light went on and I changed the battery and starter but the problem still persist. I took it to get diagnosed twice to two other locations, and the volt meter read 12 volts, but the battery display is still on, any ideas?

 

Carlos, if your battery light is on when the engine is running, then that is telling you that the alternator is not outputting the required voltage. It doesn't mean that your battery is bad (contrary to what the picture points out). Think of it more as "you are now running on the battery".

What I want you to try. If you look on the end of the left stalk (turn signal stalk), you have the selector button there. I want you to press and hold that button down and start the car at the same time. Continue to hold the button until you see the message center display something. Now, release the button on the end of the turn signal stalk. From here, repeatedly press the button till you see the message center say "Batt" with a number on the line below. This is the voltage that the computer in your car is seeing. It should be up around 13.7. If it is down around 12.5 or less, then you are definitely on the battery. This can be caused by a few things. More than likely, you are having an issue with a bad battery cable. Replace both battery cables and see what you have at that point. From there, look at the fuse box and replace the power cable running out of the fuse box. If you are still having issues, let me know and I will give you some more things to measure with a multimeter to prove things are either good or bad in your car.