AUTO-ZEROING TPS ADJ. AND ECM CONTROL SPECS. GMC Truck Caballero 1987

For 1990-2009 cars

# AUTO-ZEROING TPS ADJ. AND ECM CONTROL SPECS

#### MODELS: 1987 CABALLEROS EQUIPPED WITH 5.OL (VIN CODE H) ENGINES

On 1987 Caballeros, the ECM has the ability to auto-zero the TPS voltage if it is below .84 volts. This means that any voltage less than .84 will be determined by the ECM to be 0% (closed) throttle. "Scan" tools that have the ability to read the throttle blade angle should read 0% when the throttle is closed. A failure in the TPS circuit should set a Code 21.

If the voltage is within the specified range of below .84 volts, no adjustment is necessary. If the voltage is greater than .84 volts or a new TPS is installed, follow the adjustment/replacement procedure in section 6C-Engine Fuel and Section 6E-Engine Emissions of the 1987 Caballero Microfiche Service Manual and adjust to .5V +/- .05V.

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