One problem related to ignition module has been reported for the 1999 GMC Sonoma. The most recently reported issues are listed below.
When vehicle is in or out of gear engine idles, rpm will flucuate between 1600-3000 intermittently. Dealer ehas replaced idle motor, throttle positioner, new computer , and new software for computer. After several attempts to correct defect, dealer is claiming it is normal.
| Fuses And Circuit Breaker problems | |
| Underhood Wiring problems | |
| Ignition Module problems | |
| Ignition Switch problems |