Hello everyone,
So I purchased a 2004 Mach 1 with 90,000 miles that needed some work about a month ago. I've been slowly working on my list of things to fix or repair on the car. It ran great when I took it for a test drive. Drove it for about an hour before I decided to take it home. I was very happy with the way it ran at the time. The person I bought it from did a battery relocation kit to the trunk but ran the power wire underneath the car along the subframe connectors. Here is where it gets interesting and why the battery relocation is important information.
I rented a Uhaul truck and trailer to go pick it up because I did not want to drive it 600 miles back to Texas from New Mexico (where I bought it.) So myself and the owner at the time drove it onto the trailer and the car got a bit stuck going up the ramps of the trailer, it high centered essentially and shut off. I thought he may have just stalled it. But the car would not start. I looked under the car and noticed the battery wire that was zip tied to the subframe connectors were slashed and sparking against the trailer. The exterior and interior lights would come on but were extremely dim and the car would not crank at the time. So we unhooked the battery for safety reasons and pushed the car up on the trailer using a few extra bodies.
I get it home in the early morning and unload it. Wrap the exposed battery wire in electrical tape temporarily to attempt to get the car up my steep driveway. It starts just fine and I'm able to get it into the garage. I immediately disconnect the battery again for safety reasons. I ended up doing a much better battery relocation to the trunk by routing the battery power cable through the cabin of the car and of course a new 1/0 gauge wire plus a circuit breaker for safety.
While I had the car in my garage sitting, I added a bus bar (metal bar/post with 4 terminals) that has my battery wire powering it. This bus bar also has the starter wire and the engine bay fuse box wire attached to it. I also upped the gauge of the alternator wire and the fuse box wire to 1/0 gauge as well. I also upped the gauge of the engine to chassis ground wire and the battery ground wire to 1/0 gauge. No problems doing this easy wire upgrade.
I go to start it up for the first time after this upgrade. At this point it has been about two weeks since I brought this car home, I do not have a lot of time during the week to work on it. It cranks but doesn't start. I do not hear the fuel pump prime at all when the key is turned to the run position. Weird. So I start doing some digging around for anything disconnected. Could not find anything. The THEFT light is flashing as soon as I put the key in the run position. It ran with the theft light flashing when I took it for a test drive. No big deal, my 2001 GT was the same way after it got tuned. This Mach 1 is tuned by a very reputable tuner in New Mexico so I did not think much of it at the time. The inertia switch is pushed in, 12v is getting to the FPDM (fuel pump driver module) via the BLACK/PINK wire which comes directly from the CCRM and through the inertia switch but only 1.8v is coming out going to the fuel pump on BROWN/PINK. I shoot the ground of the FPDM and it's all good. I shoot the wires for continuity between the FPDM and the fuel pump, all good there. I can disconnect the fuel pump connector and wire it straight to a 12v battery and the fuel pump will run just fine. So I changed the FPDM anyways just to rule it out. Same problem, cranks but doesn't start.
So I spray some carb cleaner in the intake and the car fires up for about 3 seconds then dies. So it's clear the engine is obviously not getting fuel. Battery has 12v, check engine light IS NOT on during cranking.
So I moved on to attempt to address the THEFT light issue, since from what I understand if the THEFT system is engaged, the PCM will not activate the fuel pump although 12v may be getting to the FPDM. Correct me if I am wrong on that. So the car only came with one key from the previous owner. I decided to change the PATS transceiver in the steering column and have a locksmith come out and program new keys and "sync" the theft system again. Still the same thing. Cranks forever but does not start. The technician only charged me a $40 service fee, so that was cool on him since he didn't technically fix anything. He hooked up a different scan tool and the scan tool was not able to pull the VIN number for the car via the OBD2 port. He was able to clear a few codes which did not seem to be related to the problem (ABS something or other) but he got to a point trying to look at the PATS system in real time where the scan tool would no longer communicate with the PCM. It would say "cannot communicate with PCM."
I shot a lot of wires for shorts to ground, opens, and shot all the grounds according to a pin-out diagram of the PCM connector. All of my fuses are good. I shot continuity through the fuel pump fuse F1.14, good there. I have 12v going to F1.14. I shot 12v at fuses F2.2, F2.8, and F2.34. All had 12v. I cannot find anything wrong, no blown fuses. I cleaned up a few grounds here and there and redid some terminals, but never found anything wrong. The odometer IS NOT dashed, it reads mileage properly.
At this point I am leaning into getting my PCM repaired or replaced. I feel the battery power wire arcing against the trailer when I picked it up may have done some damage downstream to the PCM. Does anyone have ANYTHING else I should look at? I am open to any ideas. Sorry for the long post but I feel all of the information I have provided is necessary. Thanks.
So I purchased a 2004 Mach 1 with 90,000 miles that needed some work about a month ago. I've been slowly working on my list of things to fix or repair on the car. It ran great when I took it for a test drive. Drove it for about an hour before I decided to take it home. I was very happy with the way it ran at the time. The person I bought it from did a battery relocation kit to the trunk but ran the power wire underneath the car along the subframe connectors. Here is where it gets interesting and why the battery relocation is important information.
I rented a Uhaul truck and trailer to go pick it up because I did not want to drive it 600 miles back to Texas from New Mexico (where I bought it.) So myself and the owner at the time drove it onto the trailer and the car got a bit stuck going up the ramps of the trailer, it high centered essentially and shut off. I thought he may have just stalled it. But the car would not start. I looked under the car and noticed the battery wire that was zip tied to the subframe connectors were slashed and sparking against the trailer. The exterior and interior lights would come on but were extremely dim and the car would not crank at the time. So we unhooked the battery for safety reasons and pushed the car up on the trailer using a few extra bodies.
I get it home in the early morning and unload it. Wrap the exposed battery wire in electrical tape temporarily to attempt to get the car up my steep driveway. It starts just fine and I'm able to get it into the garage. I immediately disconnect the battery again for safety reasons. I ended up doing a much better battery relocation to the trunk by routing the battery power cable through the cabin of the car and of course a new 1/0 gauge wire plus a circuit breaker for safety.
While I had the car in my garage sitting, I added a bus bar (metal bar/post with 4 terminals) that has my battery wire powering it. This bus bar also has the starter wire and the engine bay fuse box wire attached to it. I also upped the gauge of the alternator wire and the fuse box wire to 1/0 gauge as well. I also upped the gauge of the engine to chassis ground wire and the battery ground wire to 1/0 gauge. No problems doing this easy wire upgrade.
I go to start it up for the first time after this upgrade. At this point it has been about two weeks since I brought this car home, I do not have a lot of time during the week to work on it. It cranks but doesn't start. I do not hear the fuel pump prime at all when the key is turned to the run position. Weird. So I start doing some digging around for anything disconnected. Could not find anything. The THEFT light is flashing as soon as I put the key in the run position. It ran with the theft light flashing when I took it for a test drive. No big deal, my 2001 GT was the same way after it got tuned. This Mach 1 is tuned by a very reputable tuner in New Mexico so I did not think much of it at the time. The inertia switch is pushed in, 12v is getting to the FPDM (fuel pump driver module) via the BLACK/PINK wire which comes directly from the CCRM and through the inertia switch but only 1.8v is coming out going to the fuel pump on BROWN/PINK. I shoot the ground of the FPDM and it's all good. I shoot the wires for continuity between the FPDM and the fuel pump, all good there. I can disconnect the fuel pump connector and wire it straight to a 12v battery and the fuel pump will run just fine. So I changed the FPDM anyways just to rule it out. Same problem, cranks but doesn't start.
So I spray some carb cleaner in the intake and the car fires up for about 3 seconds then dies. So it's clear the engine is obviously not getting fuel. Battery has 12v, check engine light IS NOT on during cranking.
So I moved on to attempt to address the THEFT light issue, since from what I understand if the THEFT system is engaged, the PCM will not activate the fuel pump although 12v may be getting to the FPDM. Correct me if I am wrong on that. So the car only came with one key from the previous owner. I decided to change the PATS transceiver in the steering column and have a locksmith come out and program new keys and "sync" the theft system again. Still the same thing. Cranks forever but does not start. The technician only charged me a $40 service fee, so that was cool on him since he didn't technically fix anything. He hooked up a different scan tool and the scan tool was not able to pull the VIN number for the car via the OBD2 port. He was able to clear a few codes which did not seem to be related to the problem (ABS something or other) but he got to a point trying to look at the PATS system in real time where the scan tool would no longer communicate with the PCM. It would say "cannot communicate with PCM."
I shot a lot of wires for shorts to ground, opens, and shot all the grounds according to a pin-out diagram of the PCM connector. All of my fuses are good. I shot continuity through the fuel pump fuse F1.14, good there. I have 12v going to F1.14. I shot 12v at fuses F2.2, F2.8, and F2.34. All had 12v. I cannot find anything wrong, no blown fuses. I cleaned up a few grounds here and there and redid some terminals, but never found anything wrong. The odometer IS NOT dashed, it reads mileage properly.
At this point I am leaning into getting my PCM repaired or replaced. I feel the battery power wire arcing against the trailer when I picked it up may have done some damage downstream to the PCM. Does anyone have ANYTHING else I should look at? I am open to any ideas. Sorry for the long post but I feel all of the information I have provided is necessary. Thanks.
