C E L

[roc0999]

I just checked it tonight and it pulled 3 codes

1st - p0113 Iat sensorhi input

2nd - p0102 maf or vac hi input

3rd - p0401 egr flow insufficient

Just wondering what would be causing these problems and how to correct, thanks

 

[bikerboy]

P0113 IAT Sensor Circuit High Input
Possible Causes
* Sensor signal circuit open (inspect wiring & connector)
* Sensor signal circuit shorted to VREF or system voltage
* Sensor is damaged or has failed
* PCM has failed
Here's a test you can run.

1. Locate the Intake Air Temperature sensor (IAT) located in the air cleaner outlet hose, just in front of the throttle body inlet, and inspect for loose or unplugged connector and repair as needed.
2. Backprobe the Grey wire and with Key On Engine Off (KOEO), and expect a voltage between 3.5 volts (50* air temp) and possibly as low as 1.0 volts (160* temp). If voltage reading is 4.6 volts or greater (-40* temp) and connections are good, replace the faulty sensor.
3. If no voltage present, unplug the sensor connector to test for an open circuit voltage of at least 4.6 volts. If still no voltage present, trace to locate and repair open in Grey wire from Intake Air Temperature sensor to pin 39 of Powertrain Control Module (PCM) connector.

 

[bikerboy]

P0102 MAF Sensor Circuit Low Input
Possible Causes
* Check for leaks at air outlet tube
* Sensor power circuit open, sensor ground circuit open
* Sensor signal circuit open (may be disconnected)
* Check for loose tube clamps near the MAF sensor
Here's a test you can run

1. Check the Mass Air Flow (MAF) sensor voltage at idle by back probing the Light Blue/Red (LB/R) wire at the sensor. The voltage should be about 0.7-1.0v depending on RPM.
2. If the voltage is less than 0.3v, check the power feed to the sensor on the Red wire. Also check the Black (BK) and Tan/Light Blue (TN/LB) wires for good ground with the sensor connected.
3. If the powers and grounds are OK, inspect the air inlet to be sure the air filter is the correct one and is properly installed, and also inspect for any debris on the sensor inlet. If all OK, replace the MAF sensor and recheck operation.

 

[bikerboy]

P0401 Insufficient EGR Flow Detected
Possible Causes
* DPFE sensor signal circuit is shorted to ground
* DPFE sensor VREF circuit is open between sensor and PCM
* DPFE sensor downstream hose off or plugged
* DPFE sensor hoses both off, loose or damaged
* DPFE sensor hoses connected wrong (reversed)
* EGR orifice tube is damaged or restricted
* PCM has failed
Here's a test you can run.

1. Check voltage of the DPFE sensor at the sensor connection on the Brown/Light Green (BN/LG) wire. If the circuit is OK, the circuits voltage will match the reading seen on the scan tool. Normal voltage should be 0.5-1.2 volts Key On Engine Off (KOEO) or at idle.
2. If the voltage reading matches the value seen on the scan tool, check for 5.0 volts measured between the Brown/White (BN/WT) wire and the Grey/Red (GY/RD) wire.
3. If the circuits check as stated, either the sensor is defective, or the sensor has a connection problem.
4. If the voltage measured on the BN/LG wire is different from the value seen on the scan tool, check the BN/LG wire for an open circuit and service it as necessary.

 

[bikerboy]

Let us know what you come up with for all 3 codes or if you need more diagnostics for it. Thanks and hope this helps.

 

[betomonroy]

I toughted that the rode wagons in Amish Country. I am impressed and already taken notes. Thanks bikerboy.

 

[fixizin]

roc, did the light come on recently, and all 3 codes appear at the same time? I have trouble believing *3* sensors going bad simultaneously... I'm thinking there's ONE cause for the 3 codes... but it hasn't hit me yet, lol. Hope it's not your PCM, or something that's clobbered a big wiring harness.

Make sure the "elephant trunk" tube between air filter and throttle body is clamped, airtight, and connected up to everything... make sure breather tube hasn't pulled out.

 

[bikerboy]

The po401 I would be willing to bet money on being the DPFE sensor.

 

[fixizin]

The po401 I would be willing to bet money on being the DPFE sensor.

Yep, that's the usual... already did mine once.

 

[roc0999]

I had checked it again recently and only the p0401 is there , not sure what happened to the other codes, could be like you said the one triggered the others, I'm going to v=change the dpfe sensor today and hopefully it will take care of the problems

 

[bikerboy]

sweet. Problems that fix themselves are always nice. Let us know how the others go. Oh and I have very good resources at my use that I pass on to you guys. Hope we fixed it!

 

[bikerboy]

Any update on the truck? All problems fixed?