Hey my '02 had the old check engine light come on this afternoon, did the three times on the key trick and got a 0122,1693 and 1690. Haven't been able to figure out what these are all about. Can anyone help? Thanks

 

P0122 (M) Throttle Position Sensor Voltage Low Throttle position sensor input below the acceptable
voltage range.

P1690 (M) Fuel Injection Pump CKP Sensor
Does Not Agree With ECM CKP
Sensor
Problem in fuel sync signal. Possible injection pump
timing problem. Low power, engine derated, or engine
stops.
P1693 (M) DTC Detected in Companion Module A fault has been generated in the companion engine
control module.

 

Have you had any particular symptoms when the check engine light came on? Dead pedal, lack of power, etc?
I would be concerned about a dying VP44...

 

Well the truck coughed once and then ran as it always does-strong, sounds like the 1690 code is pointing towards the VP44. Is the low voltage at the throttle position sensor an indicator of the VP44?

 

Not necessarily, you could have some other electrical issue causing the problem. A bad ground somewhere could cause the issue...
Do you have a fuel pressure gauge on your truck? If you do not, you should as you really do need one on a 2nd gen truck.

 

Yep I do have a pressure gauge and its reading 14psi-same as always. I did just change out both batteries. All terminals are clean and tight.

 

I guess the next step is to double check and clean the grounds.

 

I guess what is my next step? Is there an accurate way to diagnose if my VP44 is on the way to the grave or where to start looking? Thanks for the help?

 

Not much you can do really as far as the VP44 goes. Just wait until something changes I guess.
I would recommend cleaning the grounds though, there are a few of them under the hood; I have seen some really weird things happen that were caused by faulty grounds...
It is possible that your Cam position sensor is starting to give you grief as well... hard to tell at this point.

 

I feel your pain buddy, i just went round and round with my truck.

Search my last posts if you want some real world *** is going on with my truck. Mines fixed for now... https://www.dieseltruckresource.com/...t-t278943.html

My new vp44 ended up having a bad computer, but my OLD original one lasted for 2-3 years with "issues"

This new vp44 was flat out dead in 40 miles.

I did alot of reading, you REALLY should back probe the blue wire with black tracer on the APPS thats the part where your throttle cable goes to 3 bolts hold the entire assembly onto the motor. Your going to look for something above 1/2 of one volt so..... .647 is where mine was, IF ITS TRUELY LOW VOLTAGE COMING OUT, then you might be fighting a bad APPS and not a bad VP44 PUMP You can purchase a brand new APPS sensor from a guy here on this site for 160.00 shipped.

Mine tossed that low code too, HERE is the kicker....

If your computer says the APPS parameter is low, then do this.
Disconnect batteries for 1 full hour. Then reconnect.

Key on dont start, floor the gas pedal slowly, then bring it back to the top.
Key off.

Do that a few times and your ecm will relearn the parameter of the APPS, if you check the blue with black tracer and the voltage is low... post back or get in touch with us. You can adjust it, but best bet is to use a multimeter and see exactly what the APPS sensor is reading.
Ground above starter is a tricky one to get too, cant even see it too...

I did the dead pedal bull with my old vp44, turn the key off and turn it back on in about 1/2 second would fix it 99% of the time. Just food for thought.

HTH
BW

 

Hey thanks for the reply's. I think my problems are over for the time being. I took Mishkaya's advise and began at the grounds. I found a ground close to the fuse block in the engine compartment that was completely oxidised. I cleaned it up and a couple others and no more check engine light.