The PCM has the ability to increase and decrease the amount of fuel to each cylinder to provide smooth idle operation. If the fuel correction amount exceeds defined limits, a code is set. The following codes identify cylinder balance faults:
• DTC 91 — “Cylinder Balance Fault—#7 Cylinder”
• DTC 92 — “Cylinder Balance Fault—#2 Cylinder”
• DTC 93 — “Cylinder Balance Fault—#6 Cylinder”
• DTC 94 — “Cylinder Balance Fault— #5 Cylinder”
• DTC 95 — “Cylinder Balance Fault— #4 Cylinder”
• DTC 96 — “Cylinder Balance Fault—#3 Cylinder”
• DTC 97 — “Cylinder Balance Fault—#1 Cylinder”
• DTC 98 — “Cylinder Balance Fault— #8 Cylinder”
In order for one or more of these codes to set, the following conditions must be met:
• Engine at idle
• Coolant at normal temperature
• Cylinder fault must be continuous (i.e. constant)
• Fault must be out of limit for more than 2 seconds
