*** SOLVED***Fuel Pump Control Module DTC's

[opfor2]

***SOLVED***

Ended up replacing the fuel pressure sender and pulling the Fuel Control Module. I cleaned the FCM with contact cleaner and then put a light coat of dielectric grease on the connectors and now all codes are clear. Let's hope that this is a permanent fix.


Good morning, Tahoe Family,

So, I ran a scan on my 2011 Tahoe today and I got the following 4 DTCs under the Fuel Pump Control Module:

P018B= Fuel pressure sensor performance (hand in hand with P2635)
P0562- System low voltage
P2534- Ignition 1 switch circuit low voltage
P2635- Fuel pump flow performance

The fuel pressure seems to be ok when I checked via the fuel rail so do you think that the pump may be ready to go out? I do a lot of remote desert exploring and I don't want to be stranded in the middle of nowhere due to a fuel pump failure.

 

[Charlie207]

What sort of fuel pressure are you seeing at idle, and under throttle?

Either way, if I saw four codes for a fuel pump, I'd be gathering parts for a replacement.

 

[opfor2]

What sort of fuel pressure are you seeing at idle, and under throttle?

Either way, if I saw four codes for a fuel pump, I'd be gathering parts for a replacement.

Key on engine off 54 psi
Cold idle 60 psi
3000rpm 45 psi

 

[Charlie207]

Key on engine off 54 psi
Cold idle 60 psi
3000rpm 45 psi

@swathdiver can chime in, but I think after the initial startup (like 10 seconds) it should settle around 43psi, +/- 1psi, at most all engine rpms and loads.

(I'm probably getting something wrong, but that's what I remember him saying.)

 

[swathdiver]

Good morning Tahoe Family,

So, I ran a scan on my 2011 Tahoe today and I got the following 4 DTCs under the Fuel Pump Control Module:

P018B= Fuel pressure sensor performance (hand in hand with P2635)
P0562- System low voltage
P2534- Ignition 1 switch circuit low voltage
P2635- Fuel pump flow performance

The fuel pressure seems to be ok when I checked via the fuel rail so do you think that the pump may be ready to go out? I do a lot of remote desert exploring and I don't want to be stranded in the middle of nowhere due to a fuel pump failure.

Solve the P018B first. May need a new sensor or FPCM. Once that code is fixed, the others ought to go away.

Key on is 58 psi. Engine running at idle and normal speeds is 43.5 psi. WOT is 58 psi.

 

[opfor2]

Solve the P018B first. May need a new sensor or FPCM. Once that code is fixed, the others ought to go away.

Key on is 58 psi. Engine running at idle and normal speeds is 43.5 psi. WOT is 58 psi.

I ordered a new OEM sensor from rockauto yesterday and I will replace that first since it’s the easiest and cheapest to do

 

[fredcook]

My first "guess" would be an electrical fault triggering the fuel system DTC cascade / chain reaction. I've seen this often on my '08 and '13. A low battery start, glitchy ground, etc., setting off voltage DTC's, followed by a handful of DTC's related to one system or another (fuel, trans, etc.).

P018B and P2653 are symptoms. P2534 and P0562 are conditions. Conditions cause symptoms. In this case, you have two low voltage symptoms, and I venture to guess low voltage was passed to the fuel pump, which either shut down or didn't pressure up, and that set of the pressure sensor.

 

[opfor2]

My first "guess" would be an electrical fault triggering the fuel system DTC cascade / chain reaction. I've seen this often on my '08 and '13. A low battery start, glitchy ground, etc., setting off voltage DTC's, followed by a handful of DTC's related to one system or another (fuel, trans, etc.).

P018B and P2653 are symptoms. P2534 and P0562 are conditions. Conditions cause symptoms. In this case, you have two low voltage symptoms, and I venture to guess low voltage was passed to the fuel pump, which either shut down or didn't pressure up, and that set of the pressure sensor.

Does someone have the wiring diagram for the fuel pump and grounds?

 

[Fless]

www.charm.li has info for your vehicle. Hit the link below and scroll down to the Fuel Controls diagrams. Also at the top of the browser page you can click on "Repair and Diagnosis" and select your DTCs for the diagnostic paths:

System Diagram — 2011 Chevrolet Tahoe 4WD V8-5.3L Service Manual | Operation CHARM

Detailed repair manual for the 2011 Chevrolet Tahoe 4WD V8-5.3L.

charm.li

EDIT: for ground locations see the link below for an example of where G300 and G400 are:

G300 — 2011 Chevrolet Tahoe 4WD V8-5.3L Service Manual | Operation CHARM

Detailed repair manual for the 2011 Chevrolet Tahoe 4WD V8-5.3L.

charm.li

 

[opfor2]

Solve the P018B first. May need a new sensor or FPCM. Once that code is fixed, the others ought to go away.

Key on is 58 psi. Engine running at idle and normal speeds is 43.5 psi. WOT is 58 psi.

So, I replaced the fuel pressure sensor today with an OEM GM13500745, and hopefully it will resolve my Po18B code. BTW, the old sensor appears to be the original

 

[swathdiver]

So, I replaced the fuel pressure sensor today with an OEM GM13500745, and hopefully it will resolve my Po18B code. BTW, the old sensor appears to be the original

Keep us posted if you don't mind.

 

[opfor2]

Keep us posted if you don't mind.

will do, I'm going to get some miles on the truck then read codes and see what they tell me