Test Description

WARNING: This page is about a different car, the 2007 GMC Yukon XL and 2007 Chevrolet Suburban. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step numbers on the diagnostic table.

3: This step tests the indicated range signal to the manual valve that is actually selected.
5: This step tests the voltage from the TCM to the transmission AT inline 20-way connector.

DTC P1810

Step	Action	Yes	No
1	Did you perform the Diagnostic System Check - Vehicle?	Go to Step 2	Go to Diagnostic System Check - Vehicle
2	Inspect for correct transmission fluid level. Refer to Transmission Fluid Checking . Did you perform the Transmission Fluid Checking Procedure?	Go to Step 3	Go to Transmission Fluid Checking
3	Install a scan tool. Turn ON the ignition, with the engine OFF. IMPORTANT: Before clearing the DTCs, use the scan tool in order to record the ECM and TCM Freeze Frame and Failure Records. Using the Clear Info function erases the Freeze Frame and Failure Records from the ECM and TCM. Record the Freeze Frame and Failure Records. Clear the DTCs. Start the engine and idle at normal operating temperature. Apply the brake pedal. Select each transmission range: D1, D2, D3, D4, N, R, and P. Refer to Transmission Fluid Pressure Manual Valve Position Switch Logic . Does each selected transmission range match the scan tool TFP switch A/B/C display?	Go to Testing for Intermittent Conditions and Poor Connections	Go to Step 4
4	Inspect the transmission linkage from the gear select lever to the manual valve for proper adjustment. Adjust the linkage as necessary. Refer to Automatic Transmission Range Selector Lever Cable Adjustment . Did the linkage require adjustment?	Go to Step 17	Go to Step 5
5	Turn OFF the ignition. Disconnect the AT inline 20-way connector. Additional DTCs may set. Turn ON the ignition, with the engine OFF. Does the scan tool TFP Switch A/B/C parameter indicate HI for all range signal states?	Go to Step 6	Go to Step 10
6	Turn OFF the ignition. Install the J 44152 jumper harness (20 pins) on the engine side of the AT inline 20-way connector. Turn ON the ignition, with the engine OFF. Using the DMM and the J 35616 GM-approved terminal test kit, measure the voltage from TFP signal A circuit of the J 44152 to ground. Refer to Automatic Transmission Inline 20-Way Connector End View . See Special Tools . Measure the voltage from TFP signal B circuit of the J 44152 to ground. Measure the voltage from TFP signal C circuit of the J 44152 to ground. Is ignition voltage measured at all three terminals?	Go to Step 7	Go to Step 11
7	Connect a fused jumper wire from TFP signal A circuit of the J 44152 to ground while monitoring the scan tool TFP Switch A/B/C parameter. When Transmission Fluid Pressure Switch Signal A circuit is grounded, do any other signal circuits indicate Low?	Go to Step 12	Go to Step 8
8	Connect a fused jumper wire from TFP signal B circuit of the J 44152 to ground while monitoring the scan tool TFP Switch A/B/C parameter. When Transmission Fluid Pressure Switch Signal B circuit is grounded, do any other signal circuits indicate Low?	Go to Step 12	Go to Step 9
9	Connect a fused jumper wire from TFP signal C circuit of the J 44152 to ground while monitoring the scan tool TFP Switch A/B/C parameter. When Transmission Fluid Pressure Switch Signal C circuit is grounded, do any other signal circuits indicate Low?	Go to Step 12	Go to Step 13
10	Test the Transmission Fluid Pressure Switch Signal A, Signal B, and Signal C circuits of the TFP manual valve position switch that did not indicate HI for a short to ground between the TCM connectors and the AT inline 20-way connector. Refer to Testing for Short to Ground and Wiring Repairs . Did you find and correct the condition?	Go to Step 17	Go to Step 16
11	Test the Transmission Fluid Pressure Switch Signal A, Signal B, and Signal C circuits of the TFP manual valve position switch that did not indicate ignition voltage for an open between the TCM connectors and the AT inline 20-way connector. Refer to Testing for Continuity and Wiring Repairs . Did you find and correct the condition?	Go to Step 17	Go to Step 16
12	Test the affected signal circuits of the TFP manual valve position switch for a shorted together condition between the TCM connectors and the AT inline 20-way connector. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?	Go to Step 17	Go to Step 16
13	Test the Transmission Fluid Pressure Switch Signal A, Signal B, and Signal C circuits of the TFP manual valve position switch for an open or shorted condition between the TFP manual valve position switch and the AT inline 20-way connector. Refer to Circuit Testing and Wiring Repairs . Did you find a condition?	Go to Step 14	Go to Step 15
14	Replace the AT wiring harness assembly. Refer to Valve Body and Pressure Switch Replacement . Did you complete the replacement?	Go to Step 17	-
15	Replace the TFP manual valve position switch. Refer to Valve Body and Pressure Switch Replacement . Did you complete the replacement?	Go to Step 17	-
16	Replace the TCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement?	Go to Step 17	-
17	Perform the following procedure in order to verify the repair: Select DTC. Select Clear Info. Start the vehicle and idle for 5 seconds or greater. Select Specific DTC. Enter DTC P1810. Has the test run and passed?	Go to Step 18	Go to Step 2
18	With the scan tool, observe the stored information, capture info and DTC info. Does the scan tool display any DTCs that you have not diagnosed?	Go to Diagnostic Trouble Code (DTC) List - Vehicle	System OK