TPS failure

Tiny
KIMOPORTER
  • MEMBER
  • 2007 CHEVROLET TAHOE
  • 5.3L
  • V8
  • 2WD
  • AUTOMATIC
  • 170,000 MILES
My car was running and in park when it started showing all signs of TPS failures. What do I need to check?
Monday, March 19th, 2018 AT 11:56 PM

4 Replies

Tiny
MHPAUTOS
  • MECHANIC
  • 31,937 POSTS
You may get a code, you can also check the TPS with a live data scanner as this will shop throttle percentage as you open the throttle, no response with throttle on scanner will be fairly conclusive.
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Tuesday, March 20th, 2018 AT 12:30 AM
Tiny
PATENTED_REPAIR_PRO
  • MECHANIC
  • 1,853 POSTS
If you do not have a scan tool you could use a multi-meter.
Circuit/system testing:
Ignition OFF, disconnect the harness connector at the throttle body. Allow up to two minutes for the ECM to completely power down.
Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit terminal C and ground.
If greater than 5 ohms, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
Ignition ON, test for 4.8-5.2 volts between 5-volt reference circuit terminal E and ground.
If less than 4.8 volts, test 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
If greater than 5.2 volts, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
Verify the scan tool TP sensor 1 voltage is less than 0.1 volt.
If greater than 0.1 volt, test the signal circuit terminal D for a short to voltage. If the circuit tests normal, replace the ECM.
Verify the scan tool TP sensor 2 voltage is greater than 4.8 volts.
If less than 4.8 volts, test the signal circuit terminal F for a short to ground. If the circuit tests normal, replace the ECM.
Install a 3A fused jumper wire between the signal circuit terminal D and the 5-volt reference circuit terminal E of the TP sensor 1. Verify the TP sensor 1 voltage is greater than 4.8 volts.
If less than 4.8 volts, test the TP sensor 1 signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
Install a 3A fused jumper wire between the signal circuit terminal F and the low reference circuit terminal C of the TP sensor 2. Verify that the TP sensor 2 voltage is less than 0.1 volt.
If greater than 1.0 volt, test the TP sensor 2 signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
Ignition OFF, disconnect the harness connector at the ECM.
Test for less than 5 ohms of resistance on all TP sensor circuits between the following terminals:
ECM C2 signal circuit terminal 65 to TP terminal D
ECM C2 signal circuit terminal 63 to TP terminal F
ECM C2 5-volt reference circuit terminal 3 to terminal E
If greater than 5 ohms, repair the affected circuit for open/high resistance.
Test for infinite resistance between TP sensor 1 signal circuit terminal D and TP sensor signal circuit terminal F.
If less than infinite resistance, repair the short between TP sensor 1 signal circuit and TP sensor 2 signal circuit.
If all circuits test normal, replace the throttle body.
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Tuesday, March 20th, 2018 AT 8:43 AM
Tiny
KIMOPORTER
  • MEMBER
  • 2 POSTS
I totally disconnected the battery and replaced all plugs and wires. So do I have to relearn the TPS sensor and PCM?
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Tuesday, March 20th, 2018 AT 9:27 AM
Tiny
PATENTED_REPAIR_PRO
  • MECHANIC
  • 1,853 POSTS
I would say no. If the engine runs rough do drive it around for twenty minutes or so but I think the PCM will hold that memory in like a read only memory, which has to be flashed in order to overwrite and usually is not lost when losing the battery, like on the older types OBDI.
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Tuesday, March 20th, 2018 AT 9:41 AM

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