Lets talk sensors

[Dale_Lakin]

What are all the sensors and what are their function and operating specs?

Anyone up for a discussion on sensors? I will add what I can if there is some interest. Although many of you know more about them than I do and I hope some have some time to type and add input.

 

[95_stroker]

Here is a small list that I have from various sources, books,CD's etc etc. This list covers the early PSD's but I think that alot of the engine sensors are common up into the SD years also.

• AP Accelerator Pedal Position Sensor
  Load/demand input; PCM uses this to determine mass fuel desired, adjusts fuel delivery through IPR duty cycle and fuel pulse width and injection timing; 5 volts in, 0.5-0.7 volts at idle, 4.5 volts at WOT.
• BARO Barometric Pressure Sensor
  Strategy input; PCM uses this to adjust fuel quantity and injection timing for optimum running and minimum smoke, also glow plug on time to aid starting at higher altitudes; 5 volts in, @ 4.6 volts/14.7 psi at sea level, decreasing as altitude increases.
• CMP Camshaft Posistion Sensor
  Strategy and load input; PCM uses this to monitor engine speed to determine engine state and load, and cylinder position in order to control timing and fuel delivery; Hall Effect sensor which generates a digital voltage signal; high: 12 volts, low: 1.5 volts.
• DTC Diagnostic Trouble Code
  System malfunction or fault codes stored in the PCM to aid in diagnosis.
• EBP Exhaust Backpressure Sensor
  Feedback input; PCM uses this to monitor and control EPR operation; 5.0 volts in, 0.8-1.0 volts/14.7 psi KOEO or at idle, increases with engine RPM/load, decreases as altitude increases.
• EOT Engine Oil Temperature Sensor
  Strategy input; PCM uses this for determining glow plug on time, EPR actuation, idle speed, fuel delivery and injection timing and adjusts as temperature increases; 5.0 volts in, 4.37 volts@32°F, 1.37 volts @ 176°F, .96 volts @ 205°F.
• EPR Exhaust Backpressure Regulator, also EBP Regulator
  Output. For quicker engine warm-up at cold temperatures. If the IAT is below 37°F (50°F on some models) and the EOT is below 140°F (168° on some models) the PCM sends a duty cycle signal to a solenoid which controls oil flow from the turbo pedestal. This causes a servo to close a valve at the turbo exhaust outlet. The PCM monitors the EBP input to determine if the EPR needs to be disabled to provide power for increased load, then reapplies the EPR as load demand decreases until EOT or IAT rises.
• GPC Glow Plug Control
  Output. The PCM energizes the glow plug relay for 10 to 120 seconds depending on EOT and BARO.
• GPL Glow Plug Light
  Output. The PCM controls the "Wait to Start" light independently from the GPC output. 1 to 10 seconds depending on EOT and BARO.
• GPM Glow Plug Monitor
  Feedback input. On 1997 and newer California emission vehicles, the PCM monitors glow plug relay output voltage to determine if any glow plugs are burned out or if the relay is functioning.
• IAT Intake Air Temperature Sensor
  Strategy input. The PCM uses this for EPR control. 5 volts in, 3.897 volts @ 32°F, 3.09 volts @ 68°F, 1.72 volts @ 122°F.
• ICP Injection Control Pressure Sensor
  Feedback input. The PCM monitors the high pressure oil system to determine if it needs to be increased if load demand increases. It also uses this to stabilize idle speed. Volts in: 1.0 volt @ 580 psi, 3.22 volts @ 2520 psi.
• IDM Injector Driver Module
  The PCM sends a Cylinder Identification and Fuel Demand Control signal to the IDM. The IDM sends a 110 volt signal to the injectors. It then grounds each injector as fuel is required for that cylinder. Fuel Pulse width is increased to deliver more fuel. The IDM sends a feedback signal to the PCM for fault detection.
• IPR Injection Pressure Regulator
  Output. The PCM controls the high pressure oil system by varying the duty cycle of the IPR. The IPR controls the oil bypass circuit of the high pressure pump. 0% = full return to sump (open valve), 100% = full flow to injectors (closed valve). The PCM monitors the system with the ICP input. The PCM can control fuel delivery to the injectors by increasing the IPR duty cycle which increases fuel pressure through the injector nozzles.
• IVS Idle Validation Switch
  Strategy input. On-off switch that the PCM uses to identify required operating mode; idle or power. 0 volts at idle, 12 volts off idle.
• MAP Manifold Absolute Pressure Sensor
  Strategy and feedback input. The PCM monitors manifold pressure to control fuel delivery in order to minimize smoke. It also optimizes injection timing for detected boost. It also monitors boost to limit fuel delivery to control maximum turbo boost. Frequency output: 111Hz = 14.7 psi, 130Hz = 20 psi, 167Hz = 30 psi.
• MIL Malfunction Indicator Lamp
  "Check Engine" or "Service Engine" light that the PCM illuminates when certain system faults are present.
• PCM Powertrain Control Module, also ECU or ECM for Electronic Control Unit or Module
  The computer which monitors sensor inputs and calculates the necessary output signals to the engine control systems. It also checks for readings outside of normal parameters and records trouble codes for these faults.
• PID Parameter Identification, also Data Stream or Sensor Data
  Sensor readings displayed to a scan tool that represent sensor readings to and output signals from the PCM.

 

[wideopen]

• BARO Barometric Pressure Sensor
  Strategy input; PCM uses this to adjust fuel quantity and injection timing for optimum running and minimum smoke, also glow plug on time to aid starting at higher altitudes; 5 volts in, @ 4.6 volts/14.7 psi at sea level, decreasing as altitude increases.

If this goes bad...will that effect Fuel Millage???

How can you check this???

 

[Ford_Forgotton]

If this goes bad...will that effect Fuel Millage???

How can you check this???

On the 99 up trucks, the BARO is actually IN the computer. Older trucks the BARO was external.

BARO errors should be reported by the ODB software, but you will need a scanner to look for it.

The autoenginuity scanner can actually get INTO the sensors and display what the sensor is sending to the computer. Very cool!

 

[Ford_Forgotton]

• AP Accelerator Pedal Position Sensor
  Load/demand input; PCM uses this to determine mass fuel desired, adjusts fuel delivery through IPR duty cycle and fuel pulse width and injection timing; 5 volts in, 0.5-0.7 volts at idle, 4.5 volts at WOT.

• 
  I believe there is something called a "power pedal" mod that makes sure the computer see the maximum voltage with no fluctuations
  
  

  [*]CMP Camshaft Posistion Sensor
  Strategy and load input; PCM uses this to monitor engine speed to determine engine state and load, and cylinder position in order to control timing and fuel delivery; Hall Effect sensor which generates a digital voltage signal; high: 12 volts, low: 1.5 volts.

  Notorious for killing trucks. Without the CPS signal, the computer shuts down the injectors. Always keep a spare!
  
  

  [*]EBP Exhaust Backpressure Sensor
  Feedback input; PCM uses this to monitor and control EPR operation; 5.0 volts in, 0.8-1.0 volts/14.7 psi KOEO or at idle, increases with engine RPM/load, decreases as altitude increases.

  Very common to get an error code for the EBPS because the sensor tube fills with soot and plugs up. You can solder a resistor across two of the wires to trick the computer into thinking the EBPS is working correctly.
  
  

  [*]EOT Engine Oil Temperature Sensor
  Strategy input; PCM uses this for determining glow plug on time, EPR actuation, idle speed, fuel delivery and injection timing and adjusts as temperature increases; 5.0 volts in, 4.37 volts@32°F, 1.37 volts @ 176°F, .96 volts @ 205°F.

  Another resistor trick allows you to trick the engine oil temp signal so that the computer thinks the engine is cold and advances the timing for more power. Be careful with this, as some chips advance the timing and too much timing = BOOM!
  
  

  [*]ICP Injection Control Pressure Sensor
  Feedback input. The PCM monitors the high pressure oil system to determine if it needs to be increased if load demand increases. It also uses this to stabilize idle speed. Volts in: 1.0 volt @ 580 psi, 3.22 volts @ 2520 psi.

  The 10k mod. A 3rd resistor trick. Fools the computer into thinking the oil pressure from the HPOP is low and boosts the IPR duty cycle to gain a higher injector pressure. Good for about 30hp and 100ft/lbs on a stock truck. Less on modded trucks.
  
  

  [*]IDM Injector Driver Module
  The PCM sends a Cylinder Identification and Fuel Demand Control signal to the IDM. The IDM sends a 110 volt signal to the injectors. It then grounds each injector as fuel is required for that cylinder. Fuel Pulse width is increased to deliver more fuel. The IDM sends a feedback signal to the PCM for fault detection.

  The "joe servo" mod replaces one surface mount component inside to boost the injector voltage to around 140 volts. Its a "secret" mod that very few know the exact details too, and refuse to talk about it. Only a couple of vendors do the mod, and they charge WAY to much for a potentially useless mod. Some folks have seen no changes after doing it.
  
  

  [*]MAP Manifold Absolute Pressure Sensor
  Strategy and feedback input. The PCM monitors manifold pressure to control fuel delivery in order to minimize smoke. It also optimizes injection timing for detected boost. It also monitors boost to limit fuel delivery to control maximum turbo boost. Frequency output: 111Hz = 14.7 psi, 130Hz = 20 psi, 167Hz = 30 psi.

Still another resistor trick. Fools the computer into thinking the boost level is high and changes the fuel delivery curve to send maximum fuel even at low boost levels.

 

[wideopen]

Good Info guys

 

[BIG JOE]

Speed Sensor hint....

If yer Truck/Ex starts to surge a few MPH when yer on Cruise Control, yer Speed Sensor is prolly loaded up with metal grit from normal (hopefully)wear in yer Rear-End. It's a magnetic device that senses the RPMs of a notched ring/disk next to the Ring Gear in the Dif.. You may also start to see an >intermitent< ABS light.

It's located at the top, center area of the "Punkin", has a wire connector, a hold down type clamp. Easy fix, Common hand tools. Costs about 20 bucks. Takes about 20 minutes to replace.

If you start to see or feel a Surgeing (?) Just peplace it. BUT.... it's also an indicator that it's prolly time to drain, flush and replace the Rear-End Lube.

I just replaced mine (and lube), at 90K. took about an hour, or so.

Just thought I'd pass this along ?

JOE

On Edit: Not sure if "Speed Sensor" is the officail, FORD, name for this part. But it's my Shadegeneering term for it. I think you know what it is and what it does tho.....

 

[roosterdiesel]

Thanks Big Joe!

Mine surges sometimes at 70mph. I 'll be doing mine soon, just turned 83,000 miles.

 

[95_stroker]

Thanks Big Joe!

Mine surges sometimes at 70mph. I 'll be doing mine soon, just turned 83,000 miles.

We just talked about your surge problems the other night didnt we? Good info here !

 

[BIG JOE]

Thanks Big Joe!

Mine surges sometimes at 70mph. I 'll be doing mine soon, just turned 83,000 miles.

Antonio & All,

Did a tad more look'n up on this, it's called the VSS (Vehicle speed sensor).

I would think that anyone with, say, 60K+ might wana look into this 20 dollar R&R. I noticed the surgeing, sometime back, knew what it was, but just ignored it til' it got REAL noticeable. If I was doing 65, on CC with my FW in tow, when I'd go over an overpass the CC would add power (fuel), MPH would go to about 67-68, then it would "Hunt" , up and down (fuel) and settle at 65..... but >any< increase or decrease in grade would start the "Hunting" all-over again. It finaly got to where in would'nt/could'nt maintain a set speed. Not as noticeable un-loaded, but it was there.

Since I did the VSS R&R, 65 MPH IS 65 MPH... Rock Solid.... Unless a gear change is needed.

At near 3 bucks a gallon for #2 Diesel... (?)... the "HUNTING" has got to have an impact on MPGs.