matthopp

I noticed my truck would surge or feel like your foot fell off the accelerator some for the last 8K miles. Fuel pressure was low so I changed the left pump about 6K ago. Initial CEL showed 1694, 1693, and 0500- changed speed sensor yesterday. Truck still surges and finally did the momentary dead pedal this morning. FP is still good. Tach sometimes acts like a windshield wiper around the time when the surging occurs but engine still is consistent. Truck has plenty of power driving down the highway and I don’t have any problems passing people. Current mileage is 124K and almost paid off. All stock.

Current Codes from on-off method in order. (I used the snap on at work about a month ago and same codes showed up as key method).

P-PCU
1694
1693
P-Done
P-Done
P- ECU
0501
1698
P-Done

What the heck is 0501? I can’t find it anywhere here or in the manual.

Things I have changed: LP, Fuel Filters, checked grounds, reset APPS

Possibilities of problem: Crankshaft Sensor, APPS, ECM, or VP

Any ideas or suggestions?

phox_mulder

1694 and 1698 are ECM and PCM communication errors.

I'd say loose or corroded connection somewhere, bad ground on either the PCM or ECM?

Or, worse case, either the ECM or PCM are dying.


phox

matthopp

I was thinking that it may be an electrical issue; it is sporadic in the fact it may do it a few days in a row then take a week or two break. I am unable to reproduce the surging / dead pedal, even when the CEL is on.

I just have no idea what the heck P0501 is; I cannot find it anywhere.

Any tips or suggestions on what are the best ways to track down an electrical problem?