Help with engine codes

[Wrecker]

I just read the codes from my retired buddy's 01 Cummins, mostly stock: straight pipe, K&N Drop In filter.

5 codes

1. P1693
2. P0234
3. P0216
4. P0122
5. P1693 (same as first, set twice)

He's complaining of bad fuel mileage, any ideas?

 

[Cumminalong]

Gimme a sec and I'll see what they are......

 

[Cumminalong]

P0122 - Throttle Position sensor low voltage
P0216 - Injection Timing Control Circuit
P0234 - Turbocharger Overboost
P1693 - Turbocharger Control Circuit Malfunction

From that stuff right there, I'd say 1 - he needs a new MAP sensor and 2 - POSSIBLY a new throttle position sensor.

Both of those will definitely cause crappy mileage. The engine doesn't know where the throttle pedal is and it doesn't know how much boost there is.

One way to check the TPS is to use a voltmeter on it. There are 3 wires. One is ground, one is 5V supply and one is the signal wire to the ECM. In the idle position, you should be seeing ~1V. At full throttle you should see ~1.7V. Go throught the full range of motion and look for an spots where the voltage sticks or spikes.

MAP sensor.........it's easier and cheaper to just change it.