PCM Question
#1
PCM Question
I have a 1995 3.0L auto trans extra cab ranger.
it was a daily driver up until last week it wouldn't start turns over no fire
I towed it to my local mechanic and he told me that the PCM was bad.
So I brought it to another garage to get a second opinion and he agreed that the PCM was bad and the fix would be to install a new one then have the dealer flash it. Is it necessary to have it flashed? I have seen PCM's on line that say they are flashed to your VIN# Are these sites legit? Is there a place to have the PCM's
reconditioned?
Thanks in advance
Jeff
it was a daily driver up until last week it wouldn't start turns over no fire
I towed it to my local mechanic and he told me that the PCM was bad.
So I brought it to another garage to get a second opinion and he agreed that the PCM was bad and the fix would be to install a new one then have the dealer flash it. Is it necessary to have it flashed? I have seen PCM's on line that say they are flashed to your VIN# Are these sites legit? Is there a place to have the PCM's
reconditioned?
Thanks in advance
Jeff
#2
If you put in a new PCM, the PATS system will need a key entered into the chip.
Your present key will need to be programmed into the new PCM.
If you haven't already done so, disconnect the battery at the ground terminal and make sure it doesn't accidentally make contact with it _ use a rag or something.
Unplug the main harness from the PCM and clean the contacts on the unit as well as the plug _ there are many electronic contact cleaners on the market for this.
An air compressor works well to speed up evaporation of the stuff.
There will also be a bolt/stud on the firewall _ that's the PCM's ground. Ford painted these green.
Remove all the connections from the stud _ remove the stud _ clean all the green paint off of it.
Make sure that area on the fire wall is free from paint too.
I use silicon grease when I put the stud back in to keep the area from getting rusty and oxidized.
PCM's don't usually go bad, but dirty connections and bad grounds make it appear that they do.
Your present key will need to be programmed into the new PCM.
If you haven't already done so, disconnect the battery at the ground terminal and make sure it doesn't accidentally make contact with it _ use a rag or something.
Unplug the main harness from the PCM and clean the contacts on the unit as well as the plug _ there are many electronic contact cleaners on the market for this.
An air compressor works well to speed up evaporation of the stuff.
There will also be a bolt/stud on the firewall _ that's the PCM's ground. Ford painted these green.
Remove all the connections from the stud _ remove the stud _ clean all the green paint off of it.
Make sure that area on the fire wall is free from paint too.
I use silicon grease when I put the stud back in to keep the area from getting rusty and oxidized.
PCM's don't usually go bad, but dirty connections and bad grounds make it appear that they do.
#5
RF Veteran
iTrader: (1)
1995 Rangers had no PATS security, '99 with V6 engines and 01/02 for 4cyl Rangers
You can use another PCM used or new, from/for a 1995 Ranger 3.0l with automatic
2WD or 4WD shouldn't matter, but manual or automatic does, and of course engine size.
1995 was the first year Rangers got the newer model computer(PCM), the EEC-V, Ford goofed up a bit with the OBD2 protocol on this first model so many OBD2 scanners can't "talk" with it or get oddball responses.
So mechanics that don't know about this can often misdiagnose PCM issue when there is none.
With a no start but cranks fine you need to do a 50/50 test
remove air tube from intake manifold
Open throttle and Spray some Starter Fluid or gasoline in to the intake
Then crank the engine
If it starts and dies then fuel is the problem
If it doesn't start then spark is the problem
50/50
No fuel is usually failed fuse, fuel pump relay, inertia switch or fuel pump in the gas tank
No spark is often bad Crank Position(CKP) sensor, and on 3.0ls failed Cam Position sensor(CPS) can cause no start.
As Jeff said PCM is way way down on the list of possible problems, they can fail, just very very unlikely to fail
You can use another PCM used or new, from/for a 1995 Ranger 3.0l with automatic
2WD or 4WD shouldn't matter, but manual or automatic does, and of course engine size.
1995 was the first year Rangers got the newer model computer(PCM), the EEC-V, Ford goofed up a bit with the OBD2 protocol on this first model so many OBD2 scanners can't "talk" with it or get oddball responses.
So mechanics that don't know about this can often misdiagnose PCM issue when there is none.
With a no start but cranks fine you need to do a 50/50 test
remove air tube from intake manifold
Open throttle and Spray some Starter Fluid or gasoline in to the intake
Then crank the engine
If it starts and dies then fuel is the problem
If it doesn't start then spark is the problem
50/50
No fuel is usually failed fuse, fuel pump relay, inertia switch or fuel pump in the gas tank
No spark is often bad Crank Position(CKP) sensor, and on 3.0ls failed Cam Position sensor(CPS) can cause no start.
As Jeff said PCM is way way down on the list of possible problems, they can fail, just very very unlikely to fail
Last edited by RonD; 08-30-2016 at 01:21 PM.
#6
Thread
Thread Starter
Forum
Replies
Last Post
b3000help
General Technical & Electrical
3
03-21-2012 08:16 PM