DTC Code 62 Problem

[StevesTruck]

Hello, Can anyone help?
This is my first diesel truck and have had it less than a year. It's great and runs well but has one problem. If I go over a bump, the engine warning light comes on. After a few minutes or another bump, it goes out again. When I check the ECM (thanks to this site!) I find code 62, low boost. I have checked the wires at the sensor (black box on inlet manifold??) they seem to be ok. What other areas should I be Checking? :confused:

Many Thanks
Steve

[moondoggie]

Good Day!

DTC 62 is "turbo boost sensor circuit low," NOT low boost, although that's one of the things that could be wrong.

I'd plumb in a boost gauge & see what's really happening.

Blessings!

Brian Johnson, #5044

[gmctd]

Usually indicates open or intermittent connection - connector has +5v, Signal, and Ground.

Check for oxidation, corrosion, broken wire(s).

Could also be damaged sensor - try replacement sensor to verify.

[StevesTruck]

Thanks for the information guy's. I have what's probably a few stupid questions!
1) There are two sensors on the intake manifold, one square black one with three wires (black, green, grey) and a round one with two wires (black, orange). Which one is the turbo boost sensor?
2) Can I temporarily remove a sensor to add a pressure gauge?
3) Where is the ECM located on this truck.

I found out today that the truck will need an emmisions test soon!
I hope the light stays off for that!

Steve

[gmctd]

3-wire is Manifold Air Pressure (Boost), 2-wire is Intake Air Temperature.

DTC 62 does not indicate actual low Boost condition, but rather an out-of-range condition from sensor, caused by faulty connection or failing sensor.
A high failure condition DTC 63(?) exists, as well as a High Boost DTC 78 for actual high pressure level sensed.

Would not suggest removing either sensor, other than to check physical condition.

Might also check the Baro sensor on the firewall by the brake booster - similar appearance, 3-wire connector with +5v, Signal, Ground.

PCM should be above glove box

[whatnot]

You won't get a code 62 till the computer sees -6 psi, so it is not a boost problem.
It is probably either a bad sensor or a broken wire.

[StevesTruck]

Ok, a new development. I now have code 22 (accelerator pedal position 1 circut low??) joining code 62. I had been checking wires and connections around the turbo boost sensor and my next move was to change the TBS, but now I wonder if the problem is elsewhere. Maybe the wiring for these two sensors meets somewhere, or they share some mutual circuit?
Any Ideas?

Steve

[markrinker]

Have you cleaned all grounds on the vehicle? Start there - you are receiving unrelated out of range codes on otherwise unrelated sensors.

If in fact your throttle position sensor fails, the truck will stall - similar to FSD failure. I replace my pedal assembly (sensor) last winter. Its not common - and about $350 from GM.

[StevesTruck]

I checked and cleaned as many connections as I could and found a couple of suspect ones. I have had no warning lights for a week or so and hopefully that's the end of it. Thanks to all who helped, it's very much appricated.

Steve smile.gif