For 1990-2009 cars

Table 1: | Transmission Range Switch Valid Input Combinations
Table 2: | DTC P0706 - Transmission Range Switch Performance

Engine Controls Components
Trans Range
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

### Circuit Description

The Transmission Range Switch is part of the Transmission Park/Neutral Position (PNP) switch mounted on the transmission manual shaft. The four inputs from the transmission range switch indicate to the PCM which position is selected by the Transmission selector lever. This information is used for ignition timing, EVAP canister purge, EGR and IAC valve operation. The combination of the four transmission range input states determine the PCM commanded shift pattern. The input voltage level at the PCM is high (B+) when the transmission range switch is open and low when the switch is closed to ground. The state of each input is represented on the scan tool as High=high voltage level, Low=low voltage level. The four parameters represent transmission range switch Parity, A, B, and C inputs respectively.

A problem with the transmission range switch adjustment which causes the PCM to detect vehicle startup while a gear position other than Park or Neutral is selected will set DTC P0706.

#### Transmission Range Switch Valid Input Combinations

Gear Selector Position | Scan Tool Trans Range PABC Display X=High 0=Low
--- | ---
P | A | B | C
Park (P) | Low | Low | High | High
Reverse (R) | High | Low | Low | High
Neutral (N) | Low | High | Low | High
Drive4 (OD) | High | High | Low | Low
Drive3 (3) | Low | Low | Low | Low
Drive2 (2) | High | Low | High | Low
Drive 1 (1) | Low | High | High | Low

### Conditions for Running the DTC

The system voltage (Ignition 1) is greater than 9 volts.

### Conditions for Setting the DTC

• | The Transmission Range Switch inputs indicate a gear position other than Park or Neutral during startup.

• | The above conditions are present for 2 consecutive startups.

### Action Taken When the DTC Sets

• | The PCM defaults to a D4 transaxle range display.

• | The PCM will not illuminate the Malfunction Indicator Lamp (MIL).

• | The PCM will store conditions which were present when the DTC set as Fail Records data only. This information will not be stored as Freeze Frame data.

### Conditions for Clearing the MIL/DTC

• | A history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.

• | DTC can be cleared by using the scan tool Clear Information function or by disconnecting the PCM battery feed.

### Diagnostic Aids

DTC P0706 set indicates a misadjusted Park Neutral Position / Transmission Range Switch.

Important: Vehicle should not be driven with transaxle range switch disconnected, as idle quality will be affected.

Review the Fail Records vehicle mileage since the diagnostic test last failed. This may help determine how often the condition that caused the DTC to be set occurs.

### Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

1. This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.

#### DTC P0706 - Transmission Range Switch Performance

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | Go to Step 2 | Go to the Powertrain On Board Diagnostic (OBD) System Check
2 | Is DTC P0705 also set? | -- | Go to DTC P0705 Trans Range Switch Circuit | Go to Step 3
3 |

1. Turn ON the ignition switch.
2. Select park transmission position.
3. Observe the scan tool Trans Range display.

Does Trans Range display indicate P-N?

--

Go to Step 4

Go to Step 5

4 |

1. Select neutral transaxle position.
2. Observe scan tool Trans Range display.

Does Trans Range display indicate P-N?

--

Go to Diagnostic Aids

Go to Step 5

5 | Observe the scan tool TR Switch P / A / B / C display. Does scan tool TR Switch P / A / B / C display the specified values? | P=Low A=Low B=Low C=Low | Go to Step 6 | Go to Step 8
6 |

1. Disconnect the Transmission Range switch 4-wire connector.
2. Observe the scan tool TR Switch P / A / B / C display.

Does scan tool TR Switch P / A / B / C display the specified values?

P=Low

A=Low

B=Low

C=Low

Go to Step 7

Go to Step 8

7 |

1. Turn OFF the ignition switch.
2. Disconnect the PCM.
3. Check the Transmission Range input wiring for being pinched or otherwise shorted to ground.
4. If a problem is found, repair as necessary. Refer to Repair Procedures in Electrical Diagnosis.

Was a problem found?

--

Go to Step 12

Go to Step 11

8 |

1. Attempt to adjust the PNP / Trans Range switch. Refer to 4L60-E Transmission On-Vehicle Service .
2. Recheck the Trans Range scan tool display with Park and Neutral selected.

Does the scan tool display P-N with Park and Neutral selected?

--

Go to Step 12

Go to Step 9

9 |

1. Check for crossed wires to the Transmission Range switch 4 wire connector.
2. If a problem is found, repair as necessary. Refer to Repair Procedures in Electrical Diagnosis.

Was a problem found?

--

Go to Step 12

Go to Step 10

10 | Replace the Transmission Range switch. Refer to 4L60-E Transmission On-Vehicle Service . Is action complete? | -- | Go to Step 12 | --
11 | Replace the PCM. Important:: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Is action complete? | -- | Go to Step 12 | --
12 |

1. Clear DTCs.
2. Observe the scan tool TR Switch P / A / B / C display while selecting each gear position.
3. Record TR Switch P / A / B / C status in each gear position.
4. Compare the scan tool display with each gear position selected to the Transmission Range Switch Valid Combinations Table.

Does the scan tool display match the Transmission Range Switch Valid Combinations table in each gear position?

--

System OK

Go to Step 2