1A-79 Engine General Information and Diagnosis:
DTC “C29” (P1654-H/L): Secondary Throttle Position Sensor (STPS) Circuit Malfunction
B817H21104019
Detected Condition and Possible Cause
Wiring Diagram
ECM coupler (Harness side)
Troubleshooting
CAUTION
!
When using the multi-circuit tester, do not strongly touch the terminal of the ECM coupler with a
needle pointed tester probe to prevent the terminal damage or terminal bend.
NOTE
After repairing the trouble, clear the DTC using SDS tool. Refer to “Use of SDS Diagnosis Reset
Procedures (Page 1A-15)”.
Detected Condition Possible Cause
C29
Signal voltage is not within the following
range.
Difference between actual throttle opening
and opening calculated by ECM is larger
than specified value.
0.15 V ≤ Sensor voltage < 4.85 V
• STP sensor maladjusted.
• STP sensor circuit open or short.
• STP sensor malfunction.
• ECM malfunction.
• STP sensor circuit shorted to Vcc or ground circuit open.
• STP sensor circuit open or shorted to the ground or Vcc
circuit open.
P1654
H
Sensor voltage is higher than specified
value.
L
Sensor voltage is lower than specified
value.
B/Br
Y/W
R
ECM
E2
STP sensor
STP
Vcc
11
29
20
I718H1110083-02
I718H1110240-01