SES Light Illuminated And DTC P0171 - keywords calibration code DTC E85 engine ethanol fuel lean learn lgd MIL P0171 PCM SES system trim
| Subject: | SES Light Illuminated and DTC P0171 |
| Models: | 2007 Chevrolet Uplander |
| Equipped with 3.9L LGD Engine (VIN Code W) |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
Some owners may comment that the SES Light came on after they began using E85 Ethanol Fuel. Upon inspection you may find DTC P0171 (Fuel Trim System Lean) stored in the Powertrain Control Module (PCM).
Recommendation/Instructions:
Confirm that the fuel tank contains a high concentration of E85 ethanol fuel. See SI for information on determining ethanol concentration. Follow the diagnostic information contained in SI and verify that the PCM has or will perform the ethanol learn. If on a Tech 2 the PCM shows that the ethanol learn did not take place (stays at 0%), then the PCM will need to be reprogrammed. Please be advised that the new calibration to correct the ethanol learn should be in TIS Broadcast 7.25 on July 2, 2007. Do not attempt to reprogram the PCM with calibrations available before that broadcast as they will not correct the condition.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
