Test Description
WARNING: This page is about a different car, the 2003 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.
The numbers below refer to the step numbers in the diagnostic procedure.
- 2
TP sensor 2 and the APP sensor 2 share a common 5-volt reference source. Diagnose DTC P1220 first if P1220 is also set. See DTC P1220: THROTTLE POSITION SENSOR 2 - VOLTAGE OUT OF RANGE . - 18
This test determines whether or not the TAC module can recognize a change in signal voltage. - 19
There are 3 separate 5-volt reference sources within the TAC module. TP sensor 1 and APP sensor 1 share 1 5-volt reference source, TP sensor 2 and APP sensor 2 share another common 5-volt reference source and APP sensor 3 uses the third by itself. This test determines whether the signal circuit is shorted to any 1 of the 5-volt reference circuits. If a short exists, the corresponding sensor voltage will be pulled low. - 20
The previous step found the signal circuit and a 5-volt reference circuit shorted together. This test isolates whether the short is in the harness or within the TAC module. - 26
When the TAC module detects a condition within the TAC system, more than 1 TAC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing 1 individual condition may correct more than 1 DTC. Disconnecting components during testing may set additional DTCs. Remember this if you review the stored information in Capture Info.