kornellred

I have posted here about this nasty little condition in the past month. The first time it happened, I cleared the check engine light by disconnecting the battery to reset the engine computer. The second time it happened, the message in the DIC went away but the check engine light stayed on so I brought it to the dealer. They could find nothing wrong - the DTC code indicated a "loose plug" in the harness somewhere. Things were good for the next three weeks.

After the trip to the dealer, I bought an OBD-II scanner that has the ability to erase and reset DTC's. If the "engine power reduced" message appeared again, I would write down the code (or codes), and log the date and time to present to the dealer, then reset the ECU and continue driving (trying to drive with this message is a nightmare, or impossible - depending on conditions).

Good thing I bought that scanner. I got that message four times this past weekend. The first two times, DTC P2135 occurred. The second two times, DTC P2176 also occurred, along with P2135. P2135 indicates a lack of correlation between the throttle position sensor and the accelerator pedal sensor voltages. P2176 indicates that the vehicle has forgotten (so to speak) how to idle (because of P2135).

For this past trip to the dealer I had the code log to present as evidence. I suppose that they would have discovered the problem eventually without my "assistance", but they discovered some "bad terminals" which they "repaired". So they did find a problem - bad terminals (corroded? broken? bent?) were repaired (cleaned? straightened? replaced?). The necessary correlation between the TPS sensor and accelerator pedal sensor voltages would logically call for good, solid, tight wiring connections.

I just wish that the service department would have been a little more forthcoming about exactly how they dealt with the problem.

An OBD-II code scanner is a really good investment if you have any interest in the technology of modern vehicles. Get one with clear and reset functions, and also the ability to scan live data (system operating parameters). You never know when you , or a friend or family member, might need such information.

masterchief1112

im supprised they did not say anything to you about clearing the codes. Its "illegal" to clear codes unless you are an ase certified tec. supposedly

405HP_Z06

That's incorrect, clearing codes isn't illegal. Disabling a component that prevents an emissions code from setting due to a malfunction or modification is illegal.

kornellred

Clearing codes will not be of any use if there is a real problem with the vehicle - because they will simply come back. In my case the "engine power reduced" condition was triggered by P2135, and that code could be generated by any number of conditions. When the first trip to the dealer did not identify a specific problem, I had to assume that my HHR had one of those transient "glitch" conditions that are so difficult to track down. For instance - it always happened within 2 or 3 minutes of start-up from cold. So clearing the code allowed me to drive the vehicle when it reached full operating temperature - until the fault progressed to where normal operation was no longer possible.

I seriously doubt that any emissions controls can be deliberately disabled or bypassed on modern engines unless tuning parameters are radically changed. And the fact that OBD-II scanners with code clearing functions are ubiquitous would seem to point to their legality. It is simply a device that gives you information.