Chevrolet P1120: TP Sensor 1 Circuit Malfunction

Is your scanner showing Chevrolet P1120?
No worries. We'll show you what it means and how to deal with it.

Presented by

Randy Worner

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Chevrolet P1120: TP Sensor 1 Circuit Malfunction

OVERVIEW

Severity

Medium

DIY Difficulty Level

Intermediate

Repair Cost

$200-$600

Can I Still Drive?

Yes (Short-term only)

What Does The Chevrolet P1120 Code Mean?

The throttle position (TP) sensor is mounted on the throttle body/TAC assembly. The sensor is actually two individual throttle position sensors within one housing. Two separate signal, ground and reference circuits are used in order to connect the TP sensor assembly and the throttle actuator control (TAC) module. The TP sensor signal voltage increases as the throttle opens. The signal circuit for TP Sensor is pulled up to reference voltage.

What Are The Symptoms Of The Chevrolet P1120 Code?

Illuminated check engine light

What Are The Potential Causes Of The Chevrolet P1120 Code?

Below are some potential causes of this DTC:

TP1 sensor signal circuit is open, shorted to ground or to power
TP1 sensor low reference circuit has high resistance condition
TP1 sensor is damaged or has failed

How Can You Fix The Chevrolet P1120 Code?

Poor terminal connection

Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Use a corresponding mating terminal to test for proper tension.

Damaged harness

Inspect the wiring harness for damage. If the harness appears to be OK, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the display may indicate the location of the fault.