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Neal, Chevy Mechanic
Category: Chevy
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Experience:  Shop Owner and Mechanic on multiple makes.
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Chevy Colorado: I have the following code from a check engine light

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I have the following code from a check engine light on my Chevy Colorado, 2004.
B0899, U1064 and P0128....any ideas how bad my repairs are?
any help would be appreciated.

I'm Neal and I am here to assist you. Only accept when you are happy with my assistance. If I can't help I will open your Question to other experts.


What kind of symptoms are you getting?

Customer: replied 6 years ago.
I was drving to work and the check engine light came on. I pulled over and noticed that my oil was very low, so I added 4 quarts of 5W40 per the manufacturers specs. So far I have no symtoms, just the light.


In this situation I would clear the codes and see if they return, there is a good chance they will not and none of these are related to the low oil.


I don't show the B0899


DTC U1064 Lost Communications With Body Control Module (BCM)- this may be nothing at all and should be cleared to see if it returns.


Here is info on the P0128- I would clear that one also and see if it returns.

An engine coolant temperature (ECT) sensor monitors the temperature of the coolant. This input is used by the powertrain control module (PCM) for engine control and as an enabling criteria for some diagnostics.

The air flow coming into the engine is accumulated and used to determine if the vehicle has been driven within the conditions that would allow the engine coolant to heat up normally to the thermostat regulating temperature. If the coolant temperature does not increase normally or does not reach the regulating temperature of the thermostat, the diagnostics that use ECT as enabling criteria may not run when expected.

This DTC will only run once per ignition cycle within the enabling conditions. If the PCM detects the calibrated amount of air flow and engine run time have been met, and the ECT has not met the minimum thermostat regulating temperature, DTC P0128 sets.

- DTCs P0101, P0102, P0103, P0112, P0113, P0117, P0118, P0502, P0503 are not set.
- The startup ECT is less than 80°C (176°F).
- The intake air temperature (IAT) is more than -7°C (+19°F).
- The engine run time is between 30 seconds and 30 minutes.
- The vehicle is driven more than 0.8 kilometers (0.5 miles) at more than 8 km/h (5 mph).
- The mass air flow (MAF) is between 20-75 g/s, with the average more than 30 g/s.

The PCM detects that:
- The calibrated amount of engine run time has been met
- The calibrated amount of engine air flow has been met
- The calibrated vehicle speed and distance have been met.
- The calibrated ECT of 80°C (176°F) has not been met

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