The battery was dead, so you jumped it. The engine started, you pulled the cables, and a few minutes later the car died. Now it will not start at all, even with a charged battery sitting in the tray.<\/p>\n
A jump can save a weak battery. It can also send a voltage spike through modules that were never meant to see that surge. On many vehicles the PCM takes the hit. On Chrysler, Dodge, Jeep, and Ram products, the TIPM is just as likely, because it sits on the same power feed as the jump points.<\/p>\n
This blog covers why a car will not start after a jump, what to check before you replace a computer, and when the spike really did kill a module.<\/p>\n
A no-start after a jump start usually means the battery was not the only victim. Reverse polarity, a cable that slipped, or a running donor car with a bad regulator can push voltage far above 14 volts for a moment. Control modules and the TIPM can fail from that pulse even if the starter still cranks.<\/p>\n
Rule out the simple leftovers first: a battery that will not hold a charge, a fuse that opened during the jump, and a TIPM that no longer powers the fuel pump. If those check out and the PCM will not communicate, the spike likely reached the computer.<\/p>\n
Work from the battery outward. The jump is the event. It is not automatically the failed part.<\/p>\n
A jump can start a car with a dead cell or a failed alternator, then leave you stranded as soon as the cables come off. That is still a no-start after a jump, but the computer may be fine.<\/p>\n
Load-test the battery and check charging voltage with the engine running, if it will stay running. A battery that drops under load, or an alternator that sits at 11 volts, explains the repeat no-start without a module failure.<\/p>\n
A spark at the clamp or a momentary short can open an ECU, ignition, or fuel-pump fuse. The starter may still crank because that circuit is separate. The engine never gets injector power, coil power, or fuel-pump voltage.<\/p>\n
Check the under-hood fuses that feed the PCM, the ASD or main relay, and the fuel pump. Replace an open fuse only after you know it is not still shorted.<\/p>\n
On many Chrysler, Dodge, Jeep, and Ram vehicles the TIPM is the power distribution module next to the battery. That is also where jumper cables often land. A surge can weld a fuel-pump relay, kill a control circuit, or leave you with a crank and no fuel.<\/p>\n
Look for a fuel pump that never primes, random electrical faults, or a no-start that began the moment the jump ended. Our TIPM module<\/a> guide explains those patterns. If the board is damaged, TIPM repair services<\/a> are the usual next step on these products, including a Ram pickup<\/a> or Durango<\/a>.<\/p>\n The powertrain computer can lose a voltage regulator, a processor, or communication after a bad jump. You may get a P0606 code<\/a>, a blank scan tool, or a crank with no injector pulse.<\/p>\n Confirm battery voltage, fuses, grounds, and TIPM outputs first. If the module has no communication and its power pins are live, the spike likely ended at the PCM. That is more common when cables were reversed or the donor vehicle was running at a high idle.<\/p>\n A deep discharge plus a jump can confuse an immobilizer. The engine cranks, the security light stays on, and fuel stays cut. The module may still be good. It just no longer recognizes the key after the voltage event.<\/p>\n Try the original key, watch the security lamp, and see whether a scan tool can read immobilizer status. Do not swap a PCM to “reset” security until the key and antenna ring have been checked.<\/p>\n The battery test and the fuel-pump prime usually split this job in two.<\/p>\n4. The PCM Failed From the Surge<\/h3>\n
5. Security or Lost Memory<\/h3>\n
How to Tell These Causes Apart<\/h2>\n