i had another check engine light today. i ran codes and had the icp too low, i new that, somehow its not getting a good connection. but i knew that, and im fixing it. anyways, i did a koeo test, and it came up with p1298, idm failure. i looked it up and alldata said if i got p1298 alone, replace idm. anyone know why my idm would fail, even tho the truck runs? and how much am i looking at for a new one?

 

Are you having any symptoms?.....
Is it running OK ?..

When I had a 1298 I needed an IDM because it wouldn't run.....

 

I second what Rick said.Maybe that's an old code from a previous failure Since it's running OK. clear it and rescan.

 

yeah its running ok, other than the icp code. i cant seem to get the connections right with this icp. i have connectors crimped like coon did, and it still is throwing codes and makeing the truck stall. i am going to try to solder it agian too, hopefully it will work. but yeah, i dont know why the idm code is there. ill rescan and let you guys know.

 

sorry i've been off so long, been a busy week, are you sure the icp isnt the problem?

 

u mean like the icp sendor? im not sure. all i know is that i am getting icp codes. i think its like 1280, too low. but i dont know why. unless, like you said, the acual icp is bad. because i have the connectors crimped onto the wire. im going to try and solder them tomorrow and if that doesnt clear it up, im gunna buy a new icp. any ideas?

 

Z1 DIAGNOSTIC TROUBLE CODE (DTC) P1280: ICP CIRCUIT LOW INPUT

• DTC P1280 indicates injector control signal circuit out of range low was detected during KOEO Self Test or during continuous diagnostic monitoring.
• Possible causes:
  • biased ICP sensor/PCM
  • open ICP sensor circuit
  • short to SIG RTN or PWR GND on ICP sensor circuit
  • open in VREF circuit
• Disconnect ICP sensor connector.
• Key on/engine off.
• Measure voltage between VREF Pin B and battery ground.

Is voltage reading 5v ±.5?
<TABLE cellSpacing=0 cellPadding=3 width="92%" border=1><TBODY><TR><TH width="50%">Yes </TH><TH width="50%">No </TH></TR><TR><TD width="50%">GO to Z2 . </TD><TD width="50%">REPAIR open in VREF Circuit 351 (BR/W). CLEAR DTCs and RETEST. </TD></TR></TBODY></TABLE>

Z2 SIGNAL RETURN CIRCUIT CHECK

• Measure voltage between VREF Pin B and signal return Pin A.

Is voltage reading 5v ±0.5?
<TABLE cellSpacing=0 cellPadding=3 width="92%" border=1><TBODY><TR><TH width="50%">Yes </TH><TH width="50%">No </TH></TR><TR><TD width="50%">GO to Z3 . </TD><TD width="50%">REPAIR open in signal return Circuit 359 (GY/R). CLEAR DTCs and RETEST. </TD></TR></TBODY></TABLE>

Z3 ICP SIGNAL CIRCUIT CHECK

• Key off.
• Disconnect PCM. Inspect for loose, damaged or pushed-out pins. Repair as necessary.
• Connect breakout box. PCM disconnected.
• Measure resistance between Pin 87 and Pin C at ICP sensor harness connector.

Is resistance less than 5 ohms?
<TABLE cellSpacing=0 cellPadding=3 width="92%" border=1><TBODY><TR><TH width="50%">Yes </TH><TH width="50%">No </TH></TR><TR><TD width="50%">GO to Z4 . </TD><TD width="50%">REPAIR open in signal Circuit 812 (DB/LG) for F-Series or 535 (LB/R) for Econoline. CLEAR DTCs and RETEST. </TD></TR></TBODY></TABLE>

Z4 VREF CIRCUIT CHECK

• Measure resistance between Test Pin 90 and Pin B at ICP sensor harness connector.

Is resistance less than 5 ohms?
<TABLE cellSpacing=0 cellPadding=3 width="92%" border=1><TBODY><TR><TH width="50%">Yes </TH><TH width="50%">No </TH></TR><TR><TD width="50%">GO to Z5 . </TD><TD width="50%">REPAIR open in VREF Circuit 351 (BR/W). CLEAR codes and RETEST. </TD></TR></TBODY></TABLE>

Z5 SIGRTN CIRCUIT CHECK

• Measure resistance between Test Pin 91 and Pin A at ICP sensor harness connector.

Is resistance less than 5 ohms?
<TABLE cellSpacing=0 cellPadding=3 width="92%" border=1><TBODY><TR><TH width="50%">Yes </TH><TH width="50%">No </TH></TR><TR><TD width="50%">GO to Z6 . </TD><TD width="50%">REPAIR open in SIG RTN Circuit 359 (GY/R). CLEAR codes and RETEST. </TD></TR></TBODY></TABLE>

Z6 SENSOR SIGNAL CIRCUIT SHORT TO GROUND

• Measure resistance between Pin 87 and Pins 25/51/76/77/91/103.

Is resistance greater than 10,000 ohms?
<TABLE cellSpacing=0 cellPadding=3 width="92%" border=1><TBODY><TR><TH width="50%">Yes </TH><TH width="50%">No </TH></TR><TR><TD width="50%">GO to Z7 . </TD><TD width="50%">REPAIR short to ground in signal wire Circuit 812 (DB/LG) for F-Series or 535 (LB/R) for Econoline. CLEAR DTCs and RETEST. </TD></TR></TBODY></TABLE>

Z7 CHECK FOR SHORT ON PIN 87

• Connect breakout box to PCM.
• Measure resistance between Pin 87 and Pins 25/91/51/76/77 and 103.

Is resistance greater than 10,000 ohms?
<TABLE cellSpacing=0 cellPadding=3 width="92%" border=1><TBODY><TR><TH width="50%">Yes </TH><TH width="50%">No </TH></TR><TR><TD width="50%">REPLACE ICP sensor. RERUN Scan Tool Diagnostic Test. </TD><TD width="50%">REPLACE PCM. REMOVE breakout box. RECONNECT ICP sensor. RERUN Scan Tool Diagnostic Test. </TD></TR></TBODY></TABLE>

 

how does it work without the resisotor? is the code still there?

 

i dont have the resistor in, i have the quick connects back to stock. it still gets codes. i think it is still an open circut, im going to test it with a colt meter today.

 

how about a raven meter? or a steeler meter?.......lol sorry i had to.
good idea, get teh volt reading before and after your connector and see if its ok

 

haha, yeah yeah, sorry for the bad typing, im a pecker... give me a break.

 

just messing with ya, i do much worse when i get to typin too fast

 

coonhunter, i should have like 5 volts at the icp correct? im gunna check it tomorrow after work. also, another question. it will spit and sputter and stall when the check engine light is off, due to the icp not getting current. but when the check engine light comes on, it runs fine. does the cel go into safe mode or what?

 

sounds like it is ignoring the icp signal when the light goes on, you should have around 4.5 volts key on engine off going into the icp. coming out you should have i think .19 volts

 

......X2........